diff --git a/.gitignore b/.gitignore
index f7ccd98..80cb434 100644
--- a/.gitignore
+++ b/.gitignore
@@ -12,3 +12,4 @@ build/
 
 # Directory created by dartdoc
 doc/api/
+/.vs
diff --git a/example/conversion.dart b/example/conversion.dart
index e52c2dd..12ff14f 100644
--- a/example/conversion.dart
+++ b/example/conversion.dart
@@ -1,20 +1,16 @@
 import 'package:poly/poly.dart';
 
 main() {
-  int correct_count = 0;
+  var correct_count = 0;
   // Because of Error that List<dynamic> isn't subtype of List<int> :
   // Either use List<num> or cast it to List<num> while passing to respective function
-  List<num> c1 = [1, 2];
-  List<List<num>> c2 = [
+  var c1 = <num>[1, 2];
+  var c2 = <List<num>>[
     [1, 2],
     [3, 4],
     [5, 6]
   ];
-  List<List<num>> c3 = []
-    ..addAll(c2)
-    ..addAll([
-      [7, 8]
-    ]);
+  var c3 = <List<num>>[...c2, [7, 8]];
 // Or use -
 //  List<List<num>> c3 = [
 //    c2,
@@ -26,30 +22,25 @@ main() {
 //Example of `toPoint()` & `pointToList()`
 //* `toPoint()` converts `List<num>` to `Point<num>`
 // * `pointToList()` converts `Point<num>` to `List<num>`
-  Point pointFromC1 = toPoint(c1);
-  List<num> listFromPoint = pointToList(pointFromC1);
-  print(
-      "${++correct_count}. toPoint(c1 = [1,2])= ${pointFromC1} with type:${pointFromC1.runtimeType} & pointToList() gives us ${listFromPoint}  with type:${listFromPoint.runtimeType}");
+  var pointFromC1 = toPoint(c1);
+  var listFromPoint = pointToList(pointFromC1);
+  print('${++correct_count}. toPoint(c1 = [1,2])= $pointFromC1 with type:${pointFromC1.runtimeType} & pointToList() gives us $listFromPoint  with type:${listFromPoint.runtimeType}');
 
 //Example of `toListOfPoint()` & `pointsToList()`
 //* `toListOfPoint()` converts `List<List<num>>` to `List<Point<num>>`
 //* `pointsToList()` converts `List<Point<num>>` to `List<List<num>>`
-  List<Point> pointsFromC2 = toListOfPoint(c2);
-  List<List<num>> listFromPoints = pointsToList(pointsFromC2);
-  print(
-      "${++correct_count}. toListOfPoint(c2 = [ [1,2], [3,4], [5,6] ])= ${pointsFromC2} with type:${pointsFromC2.runtimeType} & pointsToList() gives us ${listFromPoints}  with type:${listFromPoints.runtimeType}");
+  var pointsFromC2 = toListOfPoint(c2);
+  var listFromPoints = pointsToList(pointsFromC2);
+  print('${++correct_count}. toListOfPoint(c2 = [ [1,2], [3,4], [5,6] ])= $pointsFromC2 with type:${pointsFromC2.runtimeType} & pointsToList() gives us $listFromPoints  with type:${listFromPoints.runtimeType}');
 
 //Example of `toPolyFromListOfList()` & `listOfList()`
 //* `toPolyFromListOfList()` converts `List<List<num>>` to `Polygon`
 // * `listOfList()` returns `Polygon.points` as `List<List<num>>`
 //* Print status of List of List if they are inside our Polygon using `getList_IsListOfListInside`
 //* Print if All points in List of List inside Polygon using
-  Polygon polygonC2 = toPolyFromListOfList(c2);
-  List<List<num>> backToListC2 = polygonC2.listOfList();
-  print(
-      "${++correct_count}. toPolyFromListOfList() gives ${polygonC2.runtimeType} & backToListC2() gives back ${backToListC2.runtimeType}");
-  print(
-      "${++correct_count}. Is C3= [ C2, [7,8] ] inside Polygon C2 = ${polygonC2.getList_IsListOfListInside(c3)}");
-  print(
-      "${++correct_count}. Are All Points in C3= [ C2, [7,8] ] present inside C2 = ${polygonC2.areAllPointsInsidePolygon_List(c3)}");
+  var polygonC2 = toPolyFromListOfList(c2);
+  var backToListC2 = polygonC2.listOfList();
+  print('${++correct_count}. toPolyFromListOfList() gives ${polygonC2.runtimeType} & backToListC2() gives back ${backToListC2.runtimeType}');
+  print('${++correct_count}. Is C3= [ C2, [7,8] ] inside Polygon C2 = ${polygonC2.getList_IsListOfListInside(c3)}');
+  print('${++correct_count}. Are All Points in C3= [ C2, [7,8] ] present inside C2 = ${polygonC2.areAllPointsInsidePolygon_List(c3)}');
 }
diff --git a/example/easy_casting.dart b/example/easy_casting.dart
index bf2bd9f..321f650 100644
--- a/example/easy_casting.dart
+++ b/example/easy_casting.dart
@@ -1,96 +1,93 @@
 import 'package:poly/poly.dart';
 
 main() {
-  int correct_count = 0;
-  int exception_count = 0;
+  var correct_count = 0;
+  var exception_count = 0;
 
   //1. Correct casting
   // * casting `List<dynamic> to `List<num>`
-  List correctDynamicList = [1, 2];
-  Point correctPointFromDynamicList = toPoint(correctDynamicList.cast<num>());
+  var correctDynamicList = [1, 2];
+  var correctPointFromDynamicList = toPoint(correctDynamicList.cast<num>());
   print(
-      "${++correct_count}. Type of correctPointFromDynamicList is ${correctPointFromDynamicList.runtimeType}, while correctDynamicList was ${correctDynamicList.runtimeType} \t //See casting worked as desired");
+      '${++correct_count}. Type of correctPointFromDynamicList is ${correctPointFromDynamicList.runtimeType}, while correctDynamicList was ${correctDynamicList.runtimeType} \t //See casting worked as desired');
 
   // * casting `List<dynamic>` to `List<List<num>>`
-  List correctDynamicListOfList = [
+  var correctDynamicListOfList = [
     [1, 2],
     [3, 4]
   ];
-  List<Point> listPointFromDynamicList =
+  var listPointFromDynamicList =
       toListOfPoint(correctDynamicListOfList.cast<List<num>>());
   print(
-      "${++correct_count}. Type of listPointFromDynamicList is ${listPointFromDynamicList.runtimeType}, while correctDynamicListOfList was ${correctDynamicListOfList.runtimeType} \t //See casting worked as desired");
+      '${++correct_count}. Type of listPointFromDynamicList is ${listPointFromDynamicList.runtimeType}, while correctDynamicListOfList was ${correctDynamicListOfList.runtimeType} \t //See casting worked as desired');
 
   // * Using `toListListNum`
-  List<List<num>> l = toListListNum([correctDynamicList]);
+  List<List<num?>> l = toListListNum([correctDynamicList]);
   print(
-      "${++correct_count}. ${l} has type:${l.runtimeType} & has length:${l.length}");
+      '${++correct_count}. $l has type:${l.runtimeType} & has length:${l.length}');
 
   //  Without casting `List<dynamic>` to `List<num>` `TypeError`is thrown as shown below :
   try {
-    List wrongDynamicList = [1, 2];
+    var wrongDynamicList = [1, 2];
     var wrongPoint = toPoint(wrongDynamicList);
     print(wrongPoint.runtimeType);
   } on TypeError catch (e) {
     print(
-        "\n${++exception_count}. ${e.runtimeType} Exception handled : \n \t \u2022 ${e}");
+        '\n${++exception_count}. ${e.runtimeType} Exception handled : \n \t \u2022 $e');
   }
 
   //  2. Passing `List` instead of `List<List>`
   //  * Passing `List` instead of `List<List>` & casting it : throws `CastError` as shown below :
   //    * type `int` is not a subtype of type `List<num>` in type cast
   try {
-    List wrongDynamicList = [1, 2];
-    var wrongPoint = toListOfPoint(wrongDynamicList);
+    var wrongDynamicList = [1, 2];
+    var wrongPoint = toListOfPoint(wrongDynamicList as List<List<num>>);
     print(wrongPoint.runtimeType);
   } on TypeError catch (e) {
     print(
-        "${++exception_count}. ${e.runtimeType} Exception handled : \n \t \u2022 ${e}");
+        '${++exception_count}. ${e.runtimeType} Exception handled : \n \t \u2022 $e');
   }
   //  * Passing `List` instead of `List<List>` but, without casting it : throws `TypeError` as shown below :
   //    * type `List<dynamic>` is not a subtype of type `List<List<num>>`
   try {
-    List wrongDynamicList = [1, 2];
+    var wrongDynamicList = [1, 2];
     var wrongPoint = toListOfPoint(wrongDynamicList.cast());
     print(wrongPoint.runtimeType);
-  } on CastError catch (e) {
+  } on TypeError catch (e) {
     print(
-        "${++exception_count}. ${e.runtimeType} Exception handled : \n \t \u2022 ${e}");
+        '${++exception_count}. ${e.runtimeType} Exception handled : \n \t \u2022 $e');
   }
   // type `List<dynamic>` is not a subtype of type `List<num>` in type cast
   try {
     var l = [correctDynamicList];
-    print("${l.runtimeType}");
-    List<Point> wrongListOfList = toListOfPoint(l.cast());
-  } on CastError catch (e) {
+    print('${l.runtimeType}');
+    var wrongListOfList = toListOfPoint(l.cast());
+  } on TypeError catch (e) {
     print(
-        "${++exception_count}. ${e.runtimeType} Exception handled : \n \t \u2022 ${e}");
+        '${++exception_count}. ${e.runtimeType} Exception handled : \n \t \u2022 $e');
   }
 
   //type `List<List<dynamic>>` is not a subtype of type `List<List<num>>` in type cast
   try {
-    var l = [correctDynamicList] as List<List<num>>;
-    print("${l.runtimeType}");
-    List<Point> wrongListOfList = toListOfPoint(l.cast());
-  } on CastError catch (e) {
+    var l = [correctDynamicList];
+    print('${l.runtimeType}');
+    var wrongListOfList = toListOfPoint(l.cast());
+  } on TypeError catch (e) {
     print(
-        "${++exception_count}. ${e.runtimeType} Exception handled : \n \t \u2022 ${e}");
+        '${++exception_count}. ${e.runtimeType} Exception handled : \n \t \u2022 $e');
   }
 
   // * Using from
   // > type `List<dynamic>` is not a subtype of type `List<num>`
   try {
     var l =
-        List<List<num>>.from([correctDynamicList].toList() as List<List<num>>)
+        List<List<num>>.from([correctDynamicList].toList())
             .cast()
             .toList();
-    print("${l.runtimeType}");
-    List<Point> wrongListOfList = toListOfPoint(l.cast());
+    print('${l.runtimeType}');
+    var wrongListOfList = toListOfPoint(l.cast());
   } on TypeError catch (e) {
     print(
-        "${++exception_count}. ${e.runtimeType} Exception handled : \n \t \u2022 ${e}");
-  } on CastError catch (e) {
-    print(
-        "${++exception_count}. ${e.runtimeType} Exception handled : \n \t \u2022 ${e}");
+        '${++exception_count}. ${e.runtimeType} Exception handled : \n \t \u2022 $e');
   }
 }
diff --git a/example/exception_handling.dart b/example/exception_handling.dart
index ab7deb4..f4c6070 100644
--- a/example/exception_handling.dart
+++ b/example/exception_handling.dart
@@ -1,15 +1,15 @@
 import 'package:poly/poly.dart';
 
 main() {
-  int exception_count = 0;
+  var exception_count = 0;
   // Because of Error that List<dynamic> isn't subtype of List<int>
   // So, List a can't be used without casting
-  List<num> w1 = [1, 2, 3];
-  List<List<num>> w2 = [
+  var w1 = <num>[1, 2, 3];
+  var w2 = <List<num>>[
     [1, 2],
     [3, 4]
   ];
-  List<List<num>> c2 = [
+  var c2 = <List<num>>[
     [1, 2],
     [3, 4],
     [5, 6]
@@ -18,43 +18,43 @@ main() {
   //  Exception - 1
   ///  NeedsAtLeastThreePoints is thrown if Polygon.points contains less than 3 points
   try {
-    Polygon less_than_3 = toPolyFromListOfList(w2);
+    var less_than_3 = toPolyFromListOfList(w2);
   } on NeedsAtLeastThreePoints catch (e) {
-    print("\n");
+    print('\n');
     print(
-        "${++exception_count}. ${e.runtimeType} Exception handled : \n \t \u2022 Please provide three or more points. Current number of Points: ${e.currentPointsInPolygon()}");
+        '${++exception_count}. ${e.runtimeType} Exception handled : \n \t \u2022 Please provide three or more points. Current number of Points: ${e.currentPointsInPolygon()}');
   }
   // Exception - 2
   ///WrongSizeForPoint is thrown if to_Point has more or less than 2 element. Point has only x and y.
   try {
-    Point pointWithMoreThanXY = toPoint(w1);
+    var pointWithMoreThanXY = toPoint(w1);
   } on WrongSizeForPoint catch (e) {
     print(
-        "${++exception_count}. ${e.runtimeType} Exception handled : \n \t \u2022 Wrong size, List must have 2 element. Current Size: ${e.inputListLength()}");
+        '${++exception_count}. ${e.runtimeType} Exception handled : \n \t \u2022 Wrong size, List must have 2 element. Current Size: ${e.inputListLength()}');
   }
 
 //  Exception - 3
   /// `TypeError` is thrown if `List<dynamic>` is passed instead of `List<num>`
   /// e.g. type 'List<dynamic>' is not a subtype of type 'List<num>'
   try {
-    List dy = [1, 2];
-    var ttemp = toPoint(dy);
+    var dy = [1, 2];
+    var ttemp = toPoint(dy as List<num>);
     print(ttemp.runtimeType);
   } on TypeError catch (e) {
     print(
-        "${++exception_count}. ${e.runtimeType} Exception handled : \n \t \u2022 ${e}");
+        '${++exception_count}. ${e.runtimeType} Exception handled : \n \t \u2022 $e');
   }
 
 //  Exception - 4
   /// `CastError` example - List<num> to List<List<int>>
   try {
-    Polygon wrongPoly = toPolyFromListOfList(w1.cast());
+    var wrongPoly = toPolyFromListOfList(w1.cast());
   } on TypeError catch (e) {
     print(
-        "${++exception_count}. ${e.runtimeType} Exception handled : \n \t \u2022 ${e}");
+        '${++exception_count}. ${e.runtimeType} Exception handled : \n \t \u2022 $e');
   } catch (e) {
     print(
-        "${++exception_count}. ${e.runtimeType} handled : \n \t \u2022 ${e} || ");
+        '${++exception_count}. ${e.runtimeType} handled : \n \t \u2022 $e || ');
   }
 //  Correct Error 1
 // Error: The argument type 'List<num>' can't be assigned to the parameter type 'List<List<num>>'.
diff --git a/example/poly_example.dart b/example/poly_example.dart
index 3a841a9..dd57829 100644
--- a/example/poly_example.dart
+++ b/example/poly_example.dart
@@ -1,8 +1,8 @@
 import 'package:poly/poly.dart';
 
 main() {
-  int example_count = 0;
-  List<Point<num>> l = [
+  var example_count = 0;
+  var l = <Point<num>>[
     Point(18.4851825, 73.8498851),
     Point(18.4849214, 73.8498675),
     Point(18.4855965, 73.8520493),
@@ -12,9 +12,9 @@ main() {
   ];
 
   /// List of Points can be passed as parameter to constructor Polygon()
-  Polygon testPolygon = Polygon(l);
+  var testPolygon = Polygon(l);
   // Or Just Pass List inside constructor
-  Polygon copyOfFirstPolygon = Polygon([
+  var copyOfFirstPolygon = Polygon([
     Point(18.4851825, 73.8498851),
     Point(18.4849214, 73.8498675),
     Point(18.4855965, 73.8520493),
@@ -22,38 +22,38 @@ main() {
     Point(18.4857828, 73.8500299),
     Point(18.4851825, 73.8498851)
   ]);
-  Point in1 = Point(18.48569, 73.85067);
+  var in1 = Point(18.48569, 73.85067);
 
   /// Example of `hasSamePoint()`
   /// *Checks if 2 `Polygon` have same vertices i.e. `points`
   // * Should print `true`
   print(
-      "${++example_count}. `testPolygon` and `copyOfFirstPolygon` are same : ${testPolygon.hasSamePoints(copyOfFirstPolygon)}");
+      '${++example_count}. `testPolygon` and `copyOfFirstPolygon` are same : ${testPolygon.hasSamePoints(copyOfFirstPolygon)}');
 
   /// A Point can be checked if it's present inside the Polygon by passing [Point i] to isPointInside function
   // Should Print true
   print(
-      "${++example_count}. in1=(18.48569, 73.85067) is inside testWyse - ${testPolygon.isPointInside(in1)}");
+      '${++example_count}. in1=(18.48569, 73.85067) is inside testWyse - ${testPolygon.isPointInside(in1)}');
 
   /// X,Y can be checked if they are present inside polygon by passing [x,y] to contains function
   // Should Print true
   print(
-      "${++example_count}. Polygon a contains :(18.48569, 73.85067) - ${copyOfFirstPolygon.contains(18.48569, 73.85067)}");
+      '${++example_count}. Polygon a contains :(18.48569, 73.85067) - ${copyOfFirstPolygon.contains(18.48569, 73.85067)}');
 
   /// Multiple Points inside a List can be tested by passing it to areAllPointsInsidePolygon_ListPoint
   // Should Print true
   print(
-      "${++example_count}. All points in l are within testWyse - ${testPolygon.areAllPointsInsidePolygon_ListPoint(l)}");
+      '${++example_count}. All points in l are within testWyse - ${testPolygon.areAllPointsInsidePolygon_ListPoint(l)}');
 
   ///areAllPointsInsidePolygon_ListPoint returns true if all Point<num> are inside Polygon
   // Should Print false
-  List<Point<num>> notInsidePoints = []..addAll(l)..addAll([Point(75, 90)]);
+  var notInsidePoints = <Point<num>>[...l]..addAll([Point(75, 90)]);
   print(
-      "${++example_count}. All points in notInsidePoints are within testWyse - ${testPolygon.areAllPointsInsidePolygon_ListPoint(notInsidePoints)}");
+      '${++example_count}. All points in notInsidePoints are within testWyse - ${testPolygon.areAllPointsInsidePolygon_ListPoint(notInsidePoints)}');
   //  print("${notInsidePoints}, ${notInsidePoints.runtimeType}");
 
   /// getList_IsListOfPointInside returns List<bool> as List<Point> if List<Point> are inside Polygon
   // Should Print: [true, true, true, true, true, true, false]
   print(
-      "${++example_count}. Status of notInsidePoints - ${testPolygon.getList_IsListOfPointInside(notInsidePoints)}");
+      '${++example_count}. Status of notInsidePoints - ${testPolygon.getList_IsListOfPointInside(notInsidePoints)}');
 }
diff --git a/example/prabhag11.dart b/example/prabhag11.dart
index 3a8a383..d029ab5 100644
--- a/example/prabhag11.dart
+++ b/example/prabhag11.dart
@@ -4,13 +4,13 @@ import 'dart:io';
 
 
 void main(){
-  Polygon location_eleven = Polygon([  Point(18.507305, 73.806131), Point(18.508689, 73.806131), Point(18.509299, 73.805916), Point(18.509848, 73.805981), Point(18.512941, 73.806024), Point(18.512941, 73.803492), Point(18.512453, 73.802032), Point(18.512283, 73.800424), Point(18.511964, 73.798943), Point(18.511822, 73.798749), Point(18.513429, 73.79817), Point(18.514813, 73.797483), Point(18.514854, 73.796818), Point(18.515342, 73.796067), Point(18.515688, 73.795896), Point(18.516115, 73.795788), Point(18.517377, 73.79581), Point(18.518394, 73.794222), Point(18.519696, 73.795595), Point(18.520551, 73.796153), Point(18.523155, 73.799028), Point(18.523643, 73.800831), Point(18.523888, 73.802118), Point(18.524172, 73.80259), Point(18.524091, 73.80362), Point(18.524539, 73.804607), Point(18.524591, 73.808944), Point(18.524783, 73.809571), Point(18.524094, 73.811088), Point(18.524295, 73.81259), Point(18.525454, 73.814199), Point(18.526166, 73.814886), Point(18.524172, 73.817761), Point(18.523237, 73.818169), Point(18.5211, 73.822246), Point(18.520388, 73.823254), Point(18.520063, 73.824456), Point(18.519208, 73.827052), Point(18.517133, 73.826108), Point(18.516278, 73.824906), Point(18.514894, 73.824649), Point(18.514813, 73.824306), Point(18.513674, 73.824263), Point(18.513429, 73.824048), Point(18.511964, 73.824048), Point(18.511151, 73.824391), Point(18.51054, 73.824563), Point(18.509706, 73.825486), Point(18.507627, 73.826341), Point(18.507684, 73.827277), Point(18.506822, 73.827609), Point(18.506329, 73.826702), Point(18.505942, 73.825421), Point(18.506104, 73.82467), Point(18.507395, 73.823462), Point(18.508282, 73.822739), Point(18.509584, 73.821495), Point(18.510377, 73.820529), Point(18.510479, 73.820035), Point(18.510479, 73.819048), Point(18.510418, 73.818233), Point(18.50995, 73.815637), Point(18.509665, 73.814692), Point(18.509563, 73.813834), Point(18.50934, 73.811817), Point(18.508404, 73.810508), Point(18.508119, 73.809135), Point(18.507346, 73.807611), Point(18.507305, 73.806131),  ]);
-  Point in1 = Point(18.507305, 73.806131);
+  var location_eleven = Polygon([  Point(18.507305, 73.806131), Point(18.508689, 73.806131), Point(18.509299, 73.805916), Point(18.509848, 73.805981), Point(18.512941, 73.806024), Point(18.512941, 73.803492), Point(18.512453, 73.802032), Point(18.512283, 73.800424), Point(18.511964, 73.798943), Point(18.511822, 73.798749), Point(18.513429, 73.79817), Point(18.514813, 73.797483), Point(18.514854, 73.796818), Point(18.515342, 73.796067), Point(18.515688, 73.795896), Point(18.516115, 73.795788), Point(18.517377, 73.79581), Point(18.518394, 73.794222), Point(18.519696, 73.795595), Point(18.520551, 73.796153), Point(18.523155, 73.799028), Point(18.523643, 73.800831), Point(18.523888, 73.802118), Point(18.524172, 73.80259), Point(18.524091, 73.80362), Point(18.524539, 73.804607), Point(18.524591, 73.808944), Point(18.524783, 73.809571), Point(18.524094, 73.811088), Point(18.524295, 73.81259), Point(18.525454, 73.814199), Point(18.526166, 73.814886), Point(18.524172, 73.817761), Point(18.523237, 73.818169), Point(18.5211, 73.822246), Point(18.520388, 73.823254), Point(18.520063, 73.824456), Point(18.519208, 73.827052), Point(18.517133, 73.826108), Point(18.516278, 73.824906), Point(18.514894, 73.824649), Point(18.514813, 73.824306), Point(18.513674, 73.824263), Point(18.513429, 73.824048), Point(18.511964, 73.824048), Point(18.511151, 73.824391), Point(18.51054, 73.824563), Point(18.509706, 73.825486), Point(18.507627, 73.826341), Point(18.507684, 73.827277), Point(18.506822, 73.827609), Point(18.506329, 73.826702), Point(18.505942, 73.825421), Point(18.506104, 73.82467), Point(18.507395, 73.823462), Point(18.508282, 73.822739), Point(18.509584, 73.821495), Point(18.510377, 73.820529), Point(18.510479, 73.820035), Point(18.510479, 73.819048), Point(18.510418, 73.818233), Point(18.50995, 73.815637), Point(18.509665, 73.814692), Point(18.509563, 73.813834), Point(18.50934, 73.811817), Point(18.508404, 73.810508), Point(18.508119, 73.809135), Point(18.507346, 73.807611), Point(18.507305, 73.806131),  ]);
+  var in1 = Point(18.507305, 73.806131);
 
-  List checkPunches =[ Point(18.5124785, 73.8206602), Point(18.5112654, 73.8172661), Point(18.5016256, 73.8094801), Point(18.5115046, 73.8171069), Point(18.5109839, 73.8154427), Point(18.5112721, 73.8162126), Point(18.5163667, 73.8075354), Point(18.5124489, 73.8207613), Point(18.5127482, 73.8189808), Point(18.5060939, 73.8259163), Point(18.5114909, 73.8164503), Point(18.508175, 73.822866), Point(18.5128381, 73.8112762), Point(18.5017223, 73.8094366), Point(18.5150109, 73.8159275), Point(18.5163667, 73.8075354), Point(18.5014018, 73.80952), Point(18.5112285, 73.8171876), Point(18.5078999, 73.8229854), Point(18.5135063, 73.8159908), Point(18.5110897, 73.8176941), Point(18.5107774, 73.8157407), Point(18.5011049, 73.8096167), Point(18.5128833, 73.8181274), Point(18.514984, 73.8159425), Point(18.5082853, 73.8229171), Point(18.5109213, 73.8172806), Point(18.5019752, 73.8094272), Point(18.5036271, 73.8557149), Point(18.5112384, 73.8171174), Point(18.5112384, 73.8171174), Point(18.5112384, 73.8171174), Point(18.5114182, 73.8170969), Point(18.5019349, 73.8096291), Point(18.5149707, 73.8154424), Point(18.5111738, 73.8171607), Point(18.5111634, 73.8171551), Point(18.5120293, 73.8113572), Point(18.5012618, 73.8095137), Point(18.5124395, 73.8207164), Point(18.503084, 73.8088517), Point(18.5124448, 73.8207177), Point(18.5112947, 73.8198235), Point(18.5117293, 73.8167963), Point(18.5142932, 73.8169554), Point(18.5123237, 73.8170578), Point(18.515029, 73.8159474), Point(18.5125214, 73.8086799), Point(18.5112435, 73.817181), Point(18.5124343, 73.8206081), Point(18.5079338, 73.8228738), Point(18.5117969, 73.8117694), Point(18.5112558, 73.817308), Point(18.5115868, 73.8169698), Point(18.5115922, 73.8169871), Point(18.5615843, 73.8141527), Point(18.5035994, 73.8557277), Point(18.56675, 73.8075583), Point(18.5542636, 73.8051996), Point(18.5024549, 73.8781556), Point(18.5541433, 73.805365), Point(18.5542963, 73.8053572), Point(18.5072059, 73.8262839), Point(18.5746887, 73.76487), Point(18.5543487, 73.8055963), Point(18.5542637, 73.8053565), Point(18.5542578, 73.8054209), Point(18.5611495, 73.8149408), Point(18.5555028, 73.8057247), Point(18.554192, 73.8054267), Point(18.507693, 73.796015), Point(18.5612433, 73.8145167), Point(18.5542637, 73.8053565), Point(18.5542637, 73.8053565), Point(18.5542637, 73.8053565), Point(18.5542637, 73.8053565), Point(18.5619854, 73.7928126), Point(18.5280783, 73.8303274), Point(18.5035991, 73.8557274), Point(18.5542247, 73.8053859), Point(18.5542579, 73.8052151), Point(18.5036077, 73.8557219), Point(18.5542637, 73.8053565), Point(18.5542735, 73.805281), Point(18.5552057, 73.8160962), Point(18.5036221, 73.8557353), Point(18.5542557, 73.8051856), Point(18.5036307, 73.8557221), Point(18.5606828, 73.8148879), Point(18.5542889, 73.8054483), Point(18.5542979, 73.8055085), Point(18.5542557, 73.8051856), Point(18.5035764, 73.8557534), Point(18.5542557, 73.8051856),  ];
-  List out = [];
-  List x = [];
-  List y = [];
+  var checkPunches =[ Point(18.5124785, 73.8206602), Point(18.5112654, 73.8172661), Point(18.5016256, 73.8094801), Point(18.5115046, 73.8171069), Point(18.5109839, 73.8154427), Point(18.5112721, 73.8162126), Point(18.5163667, 73.8075354), Point(18.5124489, 73.8207613), Point(18.5127482, 73.8189808), Point(18.5060939, 73.8259163), Point(18.5114909, 73.8164503), Point(18.508175, 73.822866), Point(18.5128381, 73.8112762), Point(18.5017223, 73.8094366), Point(18.5150109, 73.8159275), Point(18.5163667, 73.8075354), Point(18.5014018, 73.80952), Point(18.5112285, 73.8171876), Point(18.5078999, 73.8229854), Point(18.5135063, 73.8159908), Point(18.5110897, 73.8176941), Point(18.5107774, 73.8157407), Point(18.5011049, 73.8096167), Point(18.5128833, 73.8181274), Point(18.514984, 73.8159425), Point(18.5082853, 73.8229171), Point(18.5109213, 73.8172806), Point(18.5019752, 73.8094272), Point(18.5036271, 73.8557149), Point(18.5112384, 73.8171174), Point(18.5112384, 73.8171174), Point(18.5112384, 73.8171174), Point(18.5114182, 73.8170969), Point(18.5019349, 73.8096291), Point(18.5149707, 73.8154424), Point(18.5111738, 73.8171607), Point(18.5111634, 73.8171551), Point(18.5120293, 73.8113572), Point(18.5012618, 73.8095137), Point(18.5124395, 73.8207164), Point(18.503084, 73.8088517), Point(18.5124448, 73.8207177), Point(18.5112947, 73.8198235), Point(18.5117293, 73.8167963), Point(18.5142932, 73.8169554), Point(18.5123237, 73.8170578), Point(18.515029, 73.8159474), Point(18.5125214, 73.8086799), Point(18.5112435, 73.817181), Point(18.5124343, 73.8206081), Point(18.5079338, 73.8228738), Point(18.5117969, 73.8117694), Point(18.5112558, 73.817308), Point(18.5115868, 73.8169698), Point(18.5115922, 73.8169871), Point(18.5615843, 73.8141527), Point(18.5035994, 73.8557277), Point(18.56675, 73.8075583), Point(18.5542636, 73.8051996), Point(18.5024549, 73.8781556), Point(18.5541433, 73.805365), Point(18.5542963, 73.8053572), Point(18.5072059, 73.8262839), Point(18.5746887, 73.76487), Point(18.5543487, 73.8055963), Point(18.5542637, 73.8053565), Point(18.5542578, 73.8054209), Point(18.5611495, 73.8149408), Point(18.5555028, 73.8057247), Point(18.554192, 73.8054267), Point(18.507693, 73.796015), Point(18.5612433, 73.8145167), Point(18.5542637, 73.8053565), Point(18.5542637, 73.8053565), Point(18.5542637, 73.8053565), Point(18.5542637, 73.8053565), Point(18.5619854, 73.7928126), Point(18.5280783, 73.8303274), Point(18.5035991, 73.8557274), Point(18.5542247, 73.8053859), Point(18.5542579, 73.8052151), Point(18.5036077, 73.8557219), Point(18.5542637, 73.8053565), Point(18.5542735, 73.805281), Point(18.5552057, 73.8160962), Point(18.5036221, 73.8557353), Point(18.5542557, 73.8051856), Point(18.5036307, 73.8557221), Point(18.5606828, 73.8148879), Point(18.5542889, 73.8054483), Point(18.5542979, 73.8055085), Point(18.5542557, 73.8051856), Point(18.5035764, 73.8557534), Point(18.5542557, 73.8051856),  ];
+  var out = [];
+  var x = [];
+  var y = [];
   /// A Point can be checked if it's present inside the Polygon by passing [Point i] to contains_p function
   print(location_eleven.isPointInside(in1));
 
@@ -22,10 +22,10 @@ void main(){
   print(out);
   var out_l = out.length;
 
-  print("\n\n $out_l");
-  List<List> fe = [];
+  print('\n\n $out_l');
+  var fe = <List>[];
 //  List Temp = [];
-  for(int i =0; i< out_l; i++){
+  for(var i =0; i< out_l; i++){
 //    x[i] = e[i].x;
 //    y[i] = e[i].y;
     var Temp = [x[i],y[i],out[i]];
@@ -33,13 +33,13 @@ void main(){
   }
 //  e.forEach(f)
 //  fe = [e, out];
-  String csv = const ListToCsvConverter().convert(fe);
+  var csv = const ListToCsvConverter().convert(fe);
 //  var fil = File('out1.csv').createSync(recursive: true);
  var file = File('out1.csv');
 //  var sink = file.openSync();
   var a = file.readAsStringSync();
   if(a.isEmpty){
-    print("Will write");
+    print('Will write');
     file.writeAsStringSync(csv);
   }
   else{
diff --git a/example/simple_csv.dart b/example/simple_csv.dart
index 7ec50ce..187a59c 100644
--- a/example/simple_csv.dart
+++ b/example/simple_csv.dart
@@ -2,8 +2,8 @@ import 'package:poly/poly.dart';
 import 'dart:io';
 
 main() async {
-  int countCSV = 0;
-  Polygon location_eleven = Polygon([
+  var countCSV = 0;
+  var location_eleven = Polygon([
     Point(18.507305, 73.806131),
     Point(18.508689, 73.806131),
     Point(18.509299, 73.805916),
@@ -74,7 +74,7 @@ main() async {
     Point(18.507346, 73.807611),
     Point(18.507305, 73.806131),
   ]);
-  List<Point<num>> checkPoints = [
+  var checkPoints = <Point<num>>[
     Point(18.5124785, 73.8206602),
     Point(18.5112654, 73.8172661),
     Point(18.5016256, 73.8094801),
@@ -171,8 +171,8 @@ main() async {
     Point(18.5542557, 73.8051856),
   ];
 
-  String nameOfIsInsideResult = "IsInside.csv";
-  String nameOfPolygon = "Polygon.csv";
+  var nameOfIsInsideResult = 'IsInside.csv';
+  var nameOfPolygon = 'Polygon.csv';
 
   // Example of `IsInsideResultWithXY_ToCSVString`
   //* Saving `ArePointsInside Results` to "IsInside.csv"
@@ -180,9 +180,9 @@ main() async {
   //  * And as `diffNameThanIsInside:"Example String"` is passed,
   //  * Header row will be `latitude,longitude,Example String`
   // Get `ArePointsInside` as CSV String - `csvOfIsInsideResult`
-  String csvOfIsInsideResult = location_eleven.IsInsideResultWithXY_ToCSVString(
+  var csvOfIsInsideResult = location_eleven.IsInsideResultWithXY_ToCSVString(
       checkPoints,
-      diffNameThanIsInside: "Example String");
+      diffNameThanIsInside: 'Example String');
   // Write `String csvOfIsInsideResult` to "IsInside.csv"
   File(nameOfIsInsideResult).writeAsStringSync(csvOfIsInsideResult);
   print('${++countCSV}. ArePointsInside Results saved to IsInside.csv ');
@@ -192,7 +192,7 @@ main() async {
   //  * Headers row will be added, as `includeHeader` isn't passed as `false`
   //  * And as `useXY` is passed as `true`
   //  * Header row will be `x,y`
-  String csvOfPolygon = location_eleven.toCSVString(useXY: true);
+  var csvOfPolygon = location_eleven.toCSVString(useXY: true);
   // Write `String csvOfIsInsideResult` to "Polygon.csv"
   File(nameOfPolygon).writeAsStringSync(csvOfPolygon);
   print('${++countCSV}. `Polygon.points` saved to Polygon.csv ');
@@ -203,13 +203,13 @@ main() async {
   //* As, previously `xY_IsInside_ToCSVString` returned String with header
   //* because optional parameter `header` was not set to false
   final IsInsideList = File(nameOfIsInsideResult).openRead();
-  final l = await csvToListOfList(IsInsideList);
-  print("${++countCSV}. e.g. here ${l[0][1]} and ${l[0][2]}");
+  final l = await (csvToListOfList(IsInsideList) as Future<List<List<dynamic>>>);
+  print('${++countCSV}. e.g. here ${l[0][1]} and ${l[0][2]}');
 
   // Example of `csvToPoly`
   //* Check if Point(18.507305, 73.806131) is inside Polygon readPolygon (Polygon from Polygon.csv)
   final readPolygon = File(nameOfPolygon).openRead();
-  Polygon newPolygon = await csvToPoly(readPolygon);
+  var newPolygon = await csvToPoly(readPolygon);
   print(
-      "${++countCSV}. Is Point(18.507305, 73.806131) inside Polygon (saved in Polygon.csv) : ${newPolygon.contains(18.507305, 73.806131)}");
+      '${++countCSV}. Is Point(18.507305, 73.806131) inside Polygon (saved in Polygon.csv) : ${newPolygon.contains(18.507305, 73.806131)}');
 }
diff --git a/example/spreadsheet_example.dart b/example/spreadsheet_example.dart
index 8aab008..f9154ef 100644
--- a/example/spreadsheet_example.dart
+++ b/example/spreadsheet_example.dart
@@ -49,7 +49,7 @@
 ////void updatecell(){
 ////  var file = "poly1.xlsx";
 ////  //createFileRecursively(file);
-////  var bytes = new File(file).readAsBytesSync();
+////  var bytes = File(file).readAsBytesSync();
 ////  var decoder = SpreadsheetDecoder.decodeBytes(bytes, update: true);
 ////  var table = decoder.tables['Sheet1'];
 ////  var values = table.rows[0];
@@ -64,7 +64,7 @@
 //  // unexpected behaviour - add new column with value c instated of adding/updating cell - A3 with value c
 //  var file = "poly1.xlsx";
 //  String workSheet = 'Sheet1';
-//  var bytes = new File(file).readAsBytesSync();
+//  var bytes = File(file).readAsBytesSync();
 //  var decoder = SpreadsheetDecoder.decodeBytes(bytes, update: true);
 //  //1
 //  //  print(numberOfWorksheet(decoder));
diff --git a/example/using_to.dart b/example/using_to.dart
index eb6ab88..27db5ea 100644
--- a/example/using_to.dart
+++ b/example/using_to.dart
@@ -1,11 +1,11 @@
 import 'package:poly/poly.dart';
 
 main() {
-  int correct_count = 0;
-  int exception_count = 0;
-  List correctDynamicList = [1, 2, 'a', 3];
+  var correct_count = 0;
+  var exception_count = 0;
+  var correctDynamicList = [1, 2, 'a', 3];
   // listOf is `List<dynamic>
-  List listOf = [
+  var listOf = [
     [1, true],
     [2, 'Remove me'],
     [3, 4],
@@ -14,45 +14,45 @@ main() {
   ];
 
   print(
-      "\u2022 Old List:${correctDynamicList} has type:${correctDynamicList.runtimeType} & has length:${correctDynamicList.length}");
+      '\u2022 Old List:$correctDynamicList has type:${correctDynamicList.runtimeType} & has length:${correctDynamicList.length}');
   // * Example of `toListNum` without any optional parameters
-  List<num> l = toListNum(correctDynamicList);
+  var l = toListNum(correctDynamicList);
   print(
-      "${++correct_count}. Using `toListNum`,${l} has type:${l.runtimeType} & has length:${l.length}");
+      '${++correct_count}. Using `toListNum`,$l has type:${l.runtimeType} & has length:${l.length}');
 
   // * Example of `toListNum` with `replaceWithZero: true` and `sizeTwo: false`
-  List<num> lSizeNotTwo_Zero =
+  var lSizeNotTwo_Zero =
       toListNum(correctDynamicList, replaceWithZero: true, sizeTwo: false);
   print(
-      "${++correct_count}. Using `toListNum` with `replaceWithZero: true` and `sizeTwo: false`,${lSizeNotTwo_Zero} has type:${lSizeNotTwo_Zero.runtimeType} & has length:${lSizeNotTwo_Zero.length}");
+      '${++correct_count}. Using `toListNum` with `replaceWithZero: true` and `sizeTwo: false`,$lSizeNotTwo_Zero has type:${lSizeNotTwo_Zero.runtimeType} & has length:${lSizeNotTwo_Zero.length}');
 
   // * Example of `toListNum` with `sizeTwo: false`
-  List<num> lSizeNotTwo = toListNum(correctDynamicList, sizeTwo: false);
+  var lSizeNotTwo = toListNum(correctDynamicList, sizeTwo: false);
   print(
-      "${++correct_count}. Using `toListNum` with `sizeTwo: false`,${lSizeNotTwo} has type:${lSizeNotTwo.runtimeType} & has length:${lSizeNotTwo.length}");
+      '${++correct_count}. Using `toListNum` with `sizeTwo: false`,$lSizeNotTwo has type:${lSizeNotTwo.runtimeType} & has length:${lSizeNotTwo.length}');
 
   // * Example of `toListListNum` without any optional parameters
   print(
-      "\n\u2022 Old List:${listOf} has type:${listOf.runtimeType} & has length:${listOf.length}");
+      '\n\u2022 Old List:$listOf has type:${listOf.runtimeType} & has length:${listOf.length}');
 
-  List<List<num>> m = toListListNum(listOf);
+  List<List<num?>> m = toListListNum(listOf);
   print(
-      "${++correct_count}. Using `toListListNum`,${m} has type:${m.runtimeType} & has length:${m.length}");
+      '${++correct_count}. Using `toListListNum`,$m has type:${m.runtimeType} & has length:${m.length}');
 
   // * Example of `toListListNum` with `swapXAndY: true`
-  List<List<num>> mSwap = toListListNum(listOf, swapXAndY: true);
+  List<List<num?>> mSwap = toListListNum(listOf, swapXAndY: true);
   print(
-      "${++correct_count}. Using `toListListNum` with `swapXAndY: true`,${mSwap} has type:${mSwap.runtimeType} & has length:${mSwap.length}");
+      '${++correct_count}. Using `toListListNum` with `swapXAndY: true`,$mSwap has type:${mSwap.runtimeType} & has length:${mSwap.length}');
 
   // * Example of `toListListNum` with `replaceWithZero: true`
-  List<List<num>> mZero = toListListNum(listOf, replaceWithZero: true);
+  List<List<num?>> mZero = toListListNum(listOf, replaceWithZero: true);
   print(
-      "${++correct_count}. Using `toListListNum` with `replaceWithZero: true`,${mZero} has type:${mZero.runtimeType} & has length:${mZero.length}");
+      '${++correct_count}. Using `toListListNum` with `replaceWithZero: true`,$mZero has type:${mZero.runtimeType} & has length:${mZero.length}');
 
   // * Example of `toListListNum` with `replaceWithZero: true` and `swapXAndY: true`
-  List<List<num>> mZeroSwap =
+  List<List<num?>> mZeroSwap =
       toListListNum(listOf, replaceWithZero: true, swapXAndY: true);
   print(
-      "${++correct_count}. Using `toListListNum` with `replaceWithZero: true` and `swapXAndY: true`,${mZeroSwap} has type:${mZeroSwap.runtimeType} & has length:${mZeroSwap.length}");
+      '${++correct_count}. Using `toListListNum` with `replaceWithZero: true` and `swapXAndY: true`,$mZeroSwap has type:${mZeroSwap.runtimeType} & has length:${mZeroSwap.length}');
 
 }
diff --git a/lib/poly.dart b/lib/poly.dart
index 93f3c36..dbee588 100644
--- a/lib/poly.dart
+++ b/lib/poly.dart
@@ -22,7 +22,7 @@ import 'package:collection/collection.dart' as check_list
 //#1      _startIsolate.<anonymous closure> (dart:isolate/runtime/libisolate_patch.dart:300:19)
 //#2      _RawReceivePortImpl._handleMessage (dart:isolate/runtime/libisolate_patch.dart:171:12)
 List listAppend(List one, List two) {
-  return []..addAll(one)..addAll(two);
+  return [...one, ...two];
 }
 //List<Point<num>> new_w = append(l,[Point(74,99)].cast<Point<num>>());
 //print("\n\n ${new_w}");
@@ -39,11 +39,13 @@ List listAppend(List one, List two) {
 //TODO - kml support
 ///* `NeedsAtLeastThreePoints` is thrown if `Polygon.points` contains less than 3 points
 class NeedsAtLeastThreePoints implements Exception {
-  int _number_of_point;
+  final int _number_of_point;
   NeedsAtLeastThreePoints(this._number_of_point);
+  
+  @override
   String toString() =>
-      "Please provide three or more points. Current number of Points: $_number_of_point";
-  int currentPointsInPolygon() => this._number_of_point;
+      'Please provide three or more points. Current number of Points: $_number_of_point';
+  int currentPointsInPolygon() => _number_of_point;
 }
 
 //TO DO - Check length of dart identifier - Not found
@@ -52,23 +54,25 @@ class NeedsAtLeastThreePoints implements Exception {
 // NotJustTwoElementsForPoint
 ///* `WrongSizeForPoint` is thrown if `to_Point()` has more or less than 2 element. Point has only x and y.
 class WrongSizeForPoint implements Exception {
-  int _length_of_list;
+  final int _length_of_list;
   WrongSizeForPoint(this._length_of_list);
+  
+  @override
   String toString() =>
-      "Wrong size, List must have 2 element. Current Size: $_length_of_list";
-  int inputListLength() => this._length_of_list;
+      'Wrong size, List must have 2 element. Current Size: $_length_of_list';
+  int inputListLength() => _length_of_list;
 }
 
 //TO DO - Casting ??
 // can we check if List<dynamic> is List<num> ?? Replace List<num> with List
 ///* returns `true` if `String` contains Space
 bool containsSpace(String inputString) {
-  return inputString.contains(" ");
+  return inputString.contains(' ');
 }
 
 /// `List<num>` to `Point`
 Point toPoint(List<num> list_of_xy) {
-  int _length_of_list_xy = list_of_xy.length;
+  var _length_of_list_xy = list_of_xy.length;
   if (_length_of_list_xy == 2) {
     return Point(list_of_xy[0], list_of_xy[1]);
   } else {
@@ -79,14 +83,14 @@ Point toPoint(List<num> list_of_xy) {
 
 ///  `Point` to `List<num>`
 List<num> pointToList(Point inPoint) {
-  List<num> output = [inPoint.x, inPoint.y];
+  final output = [inPoint.x, inPoint.y];
   return output;
 }
 
 //TODO - Add a check to see if it's List<List<num>> or just List if it's casted ?
 /// `List<List (x,y)>` to `List<Point>`
 List<Point<num>> toListOfPoint(List<List<num>> list_of_list) {
-  List<Point<num>> _out_list_of_point = [];
+  var _out_list_of_point = <Point<num>>[];
   list_of_list.forEach((_element_in_list_of_list) {
     _out_list_of_point.add(toPoint(_element_in_list_of_list));
   });
@@ -95,8 +99,8 @@ List<Point<num>> toListOfPoint(List<List<num>> list_of_list) {
 
 /// `List<Point>` to `List<List (x,y)>`
 List<List<num>> pointsToList(List<Point<num>> inputListOfPoint) {
-  List<List<num>> _out = [];
-  for (int _i = 0; _i < inputListOfPoint.length; _i++) {
+  var _out = <List<num>>[];
+  for (var _i = 0; _i < inputListOfPoint.length; _i++) {
     _out.add(pointToList(inputListOfPoint[_i]));
   }
   return _out;
@@ -108,7 +112,7 @@ Polygon toPolyFromListOfList(List<List<num>> list_of_list) {
   if (_length_of_poly < 3) {
     throw NeedsAtLeastThreePoints(_length_of_poly);
   }
-  List<Point<num>> _list_of_point = [];
+  var _list_of_point = <Point<num>>[];
   list_of_list.forEach((_element_in_list_of_list) {
     _list_of_point.add(toPoint(_element_in_list_of_list));
   });
@@ -133,8 +137,8 @@ List<num> toListNum(List _inputList,
     {bool reverseIt = false,
     bool replaceWithZero = false,
     bool sizeTwo = true}) {
-  var _list = []..addAll(_inputList);
-  int lengthOfPoints = _list.length;
+  var _list = [..._inputList];
+  var lengthOfPoints = _list.length;
   if (replaceWithZero) {
     //print("${lengthOfPoints}");
     if (sizeTwo) {
@@ -153,7 +157,7 @@ List<num> toListNum(List _inputList,
         _list = [x, 0];
       }
     } else {
-      for (int _i = 0; _i < lengthOfPoints; _i++) {
+      for (var _i = 0; _i < lengthOfPoints; _i++) {
         var element = _list[_i];
         if ((element.runtimeType == String) || (element.runtimeType == bool)) {
           _list[_i] = 0;
@@ -168,15 +172,15 @@ List<num> toListNum(List _inputList,
   lengthOfPoints = sizeTwo ? 2 : _list.length;
 
   //print("${lengthOfPoints}");
-  List<num> numList = [];
+  var numList = <num>[];
   if (reverseIt) {
-    for (int _i = lengthOfPoints - 1; _i >= 0; _i--) {
+    for (var _i = lengthOfPoints - 1; _i >= 0; _i--) {
       var x = _list[_i];
       //print(x.runtimeType);
       numList.add(x);
     }
   } else {
-    for (int _i = 0; _i < lengthOfPoints; _i++) {
+    for (var _i = 0; _i < lengthOfPoints; _i++) {
       var x = _list[_i];
       //print(x.runtimeType);
       numList.add(x);
@@ -197,20 +201,20 @@ List<num> toListNum(List _inputList,
 ///       - i.e. `[ [x1,y1], [x2,y2], ...]` -> `[ [y1,x1], [y2,x2], ...]`
 List<List<num>> toListListNum(List _inputListOfList,
     {bool swapXAndY = false, bool replaceWithZero = false}) {
-  var _listOfList = []..addAll(_inputListOfList);
+  var _listOfList = [..._inputListOfList];
   if (_listOfList[0][0].runtimeType == String) {
     swapXAndY = swapXAndY
         ? swapXAndY
-        : ((_listOfList[0][0] == "longitude" || _listOfList[0][0] == "y")
+        : ((_listOfList[0][0] == 'longitude' || _listOfList[0][0] == 'y')
             ? true
             : false);
     //_listOfList.removeAt(0);
   }
-  int lengthOfPoints = _listOfList.length;
+  var lengthOfPoints = _listOfList.length;
   //print("Before: ${lengthOfPoints}");
   if (replaceWithZero) {
     //print("${lengthOfPoints}");
-    for (int _i = 0; _i < lengthOfPoints; _i++) {
+    for (var _i = 0; _i < lengthOfPoints; _i++) {
       var x = _listOfList[_i][0];
       var y = _listOfList[_i][1];
       //print(x.runtimeType);
@@ -230,10 +234,10 @@ List<List<num>> toListListNum(List _inputListOfList,
             ((_i[1].runtimeType == String) || (_i[1].runtimeType == bool))));
   }
   lengthOfPoints = _listOfList.length;
-  List<List<num>> numList = [];
+  var numList = <List<num>>[];
 
   if (swapXAndY) {
-    for (int _i = 0; _i < lengthOfPoints; _i++) {
+    for (var _i = 0; _i < lengthOfPoints; _i++) {
       var x = _listOfList[_i][0];
       var y = _listOfList[_i][1];
       numList.add([y, x]);
@@ -248,7 +252,7 @@ List<List<num>> toListListNum(List _inputListOfList,
     }
   } else {
     //print("lengthOfPoints:${lengthOfPoints}");
-    for (int _i = 0; _i < lengthOfPoints; _i++) {
+    for (var _i = 0; _i < lengthOfPoints; _i++) {
       // print("_i:${_i}");
       var y = _listOfList[_i][1];
       var x = _listOfList[_i][0];
@@ -273,7 +277,7 @@ List<List<num>> toListListNum(List _inputListOfList,
 /// A class for representing two-dimensional Polygon defined with `List<Point<num>> points`.
 class Polygon {
   final List<Point<num>> points;
-  String name;
+  String name = '';
   // double version;
 
   ///Create a `Polygon` with vertices at `points`.
@@ -282,7 +286,7 @@ class Polygon {
     var _number_of_point = this.points.length;
     if (_number_of_point < 3) {
       throw NeedsAtLeastThreePoints(_number_of_point);
-      //  throw new ArgumentError("Please provide three or more points.");
+      //  throw ArgumentError("Please provide three or more points.");
     }
 //    name = tname;
   }
@@ -296,11 +300,11 @@ class Polygon {
   bool contains(num px, num py) {
     num ax = 0;
     num ay = 0;
-    num bx = points[points.length - 1].x - px;
-    num by = points[points.length - 1].y - py;
-    int depth = 0;
+    var bx = points[points.length - 1].x - px;
+    var by = points[points.length - 1].y - py;
+    var depth = 0;
 
-    for (int i = 0; i < points.length; i++) {
+    for (var i = 0; i < points.length; i++) {
       ax = bx;
       ay = by;
       bx = points[i].x - px;
@@ -342,10 +346,10 @@ class Polygon {
     if (isPointInside(i)) {
       return true;
     } else {
-      double dis = 0, dd = 0;
-      dis = distanceInMeter(i.x, i.y, points[0].x, points[0].y);
-      for (int j = 1; j < points.length; j++) {
-        dd = distanceInMeter(i.x, i.y, points[j].x, points[j].y);
+      var dis = 0.0, dd = 0.0;
+      dis = distanceInMeter(i.x as double, i.y as double, points[0].x as double, points[0].y as double);
+      for (var j = 1; j < points.length; j++) {
+        dd = distanceInMeter(i.x as double, i.y as double, points[j].x as double, points[j].y as double);
         dis = dd < dis ? dd : dis;
       }
       return dis > T ? false : true;
@@ -354,7 +358,7 @@ class Polygon {
 
   /// Checks if 2 `Polygon` have same vertices i.e. `points`
   bool hasSamePoints(Polygon anotherPolygon) {
-    bool same = (points.length == anotherPolygon.points.length);
+    var same = (points.length == anotherPolygon.points.length);
     if (!same) {
       return false;
     } else {
@@ -372,7 +376,7 @@ class Polygon {
 
   /// returns `List<bool>` from `List<Point<num>>` based on if `Point<num>` is present or not
   List<bool> getList_IsListOfPointInside(List<Point<num>> inputListOfPoint) {
-    List<bool> _out = [];
+    var _out = <bool>[];
     for (var _currentPoint in inputListOfPoint) {
       _out.add(isPointInside(_currentPoint));
     }
@@ -381,7 +385,7 @@ class Polygon {
 
   /// returns `List<bool>` from `List<Point<num>>` based on if `Point<num>` is present or not
   List<bool> getList_IsListOfListInside(List<List<num>> inputListOfList) {
-    List<bool> _out = [];
+    var _out = <bool>[];
     var _inputListOfPoint = toListOfPoint(inputListOfList);
     _inputListOfPoint.forEach((_currentPoint) {
       _out.add(isPointInside(_currentPoint));
@@ -398,7 +402,7 @@ class Polygon {
 
   /// returns `true` if all List<num> are inside `Polygon`
   bool areAllPointsInsidePolygon_List(List<List<num>> inputListOfList) {
-    List<Point<num>> inputListOfPoint = toListOfPoint(inputListOfList);
+    var inputListOfPoint = toListOfPoint(inputListOfList);
     return getList_IsListOfPointInside(inputListOfPoint).contains(false)
         ? false
         : true;
@@ -406,9 +410,9 @@ class Polygon {
 
   /// returns `List indexes` from `List<Point<num>>` based on which `Point<num>` are present inside
   List<int> listIndexOfInsidePoint(List<Point<num>> inputListOfPoint) {
-    List<int> _out = [];
+    var _out = <int>[];
     Point<num> _pointInList;
-    for (int index = 0; index < inputListOfPoint.length; index++) {
+    for (var index = 0; index < inputListOfPoint.length; index++) {
       _pointInList = inputListOfPoint[index];
       if (isPointInside(_pointInList)) {
         _out.add(index);
@@ -428,33 +432,33 @@ class Polygon {
   ///    * Different name than Default name(`isInside`) will be used by passing optional parameter: `diffNameThanIsInside`
   String IsInsideResultWithXY_ToCSVString(List<Point<num>> inputListOfPoint,
       {bool includeHeader = true,
-      String diffNameThanIsInside,
+      String diffNameThanIsInside = '',
       bool useXY = false}) {
-    List<List> xYOut = [];
+    var xYOut = <List>[];
     if (includeHeader) {
-      String headerX = useXY ? "x" : "latitude";
-      String headerY = useXY ? "y" : "longitude";
+      var headerX = useXY ? 'x' : 'latitude';
+      var headerY = useXY ? 'y' : 'longitude';
       // TODO - Remove three quotation marks """Example Name_with_space""" when '"x"' is used, instead of "x"
       diffNameThanIsInside = containsSpace(diffNameThanIsInside)
-          ? '${diffNameThanIsInside}'
+          ? '$diffNameThanIsInside'
           : diffNameThanIsInside;
 //      print(diffNameThanIsInside);
-      String headerIs = (diffNameThanIsInside?.isNotEmpty ?? false)
+      var headerIs = diffNameThanIsInside.isNotEmpty
           ? diffNameThanIsInside
-          : "isInside";
+          : 'isInside';
       var headerL = [headerX, headerY, headerIs];
       xYOut.add(headerL);
     }
 
     for (var _currentPoint in inputListOfPoint) {
-      bool c_out = isPointInside(_currentPoint);
+      var c_out = isPointInside(_currentPoint);
 //      _out.add(c_out);
 //      x.add(_currentPoint.x);
 //      y.add(_currentPoint.y);
       var Temp = [_currentPoint.x, _currentPoint.y, c_out];
       xYOut.add(Temp);
     }
-    String csv = const ListToCsvConverter().convert(xYOut);
+    var csv = const ListToCsvConverter().convert(xYOut);
     return csv;
   }
 
@@ -466,10 +470,10 @@ class Polygon {
   /// * Optional Named parameter: `String includeHeader`
   ///    * if optional parameter - `includeHeader` is is passed as `false`, returning String will not contain header row
   String toCSVString({bool includeHeader = true, bool useXY = false}) {
-    List<List> _xY = [];
+    var _xY = <List>[];
     if (includeHeader) {
-      String _headerX = useXY ? "x" : "latitude";
-      String _headerY = useXY ? "y" : "longitude";
+      var _headerX = useXY ? 'x' : 'latitude';
+      var _headerY = useXY ? 'y' : 'longitude';
       var _headerL = [_headerX, _headerY];
       _xY.add(_headerL);
     }
@@ -477,7 +481,7 @@ class Polygon {
       var _currentXY = [_currentPoint.x, _currentPoint.y];
       _xY.add(_currentXY);
     }
-    String csv = const ListToCsvConverter().convert(_xY);
+    var csv = const ListToCsvConverter().convert(_xY);
     return csv;
   }
 } // class Polygon
@@ -516,37 +520,37 @@ Future<Polygon> csvToPoly(var csvString, {bool isReversed = false}) async {
   if (_listOfList[0][0].runtimeType == String) {
     isReversed = isReversed
         ? isReversed
-        : ((_listOfList[0][0] == "longitude" || _listOfList[0][0] == "y")
+        : ((_listOfList[0][0] == 'longitude' || _listOfList[0][0] == 'y')
             ? true
             : false);
     _listOfList.removeAt(0);
   }
 
-  List<List<num>> numList = [];
-  int lengthOfPoints = _listOfList.length;
+  var numList = <List<num>>[];
+  var lengthOfPoints = _listOfList.length;
   if (isReversed) {
-    for (int _i = 0; _i < lengthOfPoints; _i++) {
+    for (var _i = 0; _i < lengthOfPoints; _i++) {
       var x = _listOfList[_i][0];
       var y = _listOfList[_i][1];
       //print(x.runtimeType);
       numList.add([y, x]);
     }
   } else {
-    for (int _i = 0; _i < lengthOfPoints; _i++) {
+    for (var _i = 0; _i < lengthOfPoints; _i++) {
       var y = _listOfList[_i][1];
       var x = _listOfList[_i][0];
       //print(x.runtimeType);
       numList.add([x, y]);
     }
   }
-  Polygon _out = toPolyFromListOfList(numList);
+  var _out = toPolyFromListOfList(numList);
   return _out;
 }
 
 //Future<Polygon> csvToPoly_casting_issue(var input, {bool isReversed = false}) async {
 //  List<List<num>> fields = await input
 //      .transform(utf8.decoder)
-//      .transform(new CsvToListConverter())
+//      .transform(CsvToListConverter())
 //      .toList();
 //  if (fields[0][0].runtimeType == String) {
 //    fields.removeAt(0);
@@ -565,7 +569,7 @@ Future<Polygon> csvToPoly(var csvString, {bool isReversed = false}) async {
 //Future<void> csvToTemp(var input, {bool isReversed = false}) async {
 //  List<List> fields = await input
 //      .transform(utf8.decoder)
-//      .transform(new CsvToListConverter())
+//      .transform(CsvToListConverter())
 //      .toList();
 //  if (fields[0][0].runtimeType == String) {
 //    fields.removeAt(0);
diff --git a/pubspec.yaml b/pubspec.yaml
index 7671c5b..a5127dd 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,20 +1,20 @@
 name: poly
 description: A library for checking if given point(s) is present inside Polygon or not.
-version: 1.0.7+2
+version: 1.0.8
 homepage: https://github.com/Sacchid/poly
 author: sacchi <22224760+Sacchid@users.noreply.github.com>
 
 environment:
-  sdk: '>=2.1.0 <3.0.0'
+  sdk: ">=2.12.0-0 <3.0.0"
 
 dependencies:
-  csv: ^4.0.3
-  collection: ^1.14.11
+  collection: ^1.15.0
+  csv: ^5.0.0 
 #  spreadsheet_decoder: ^1.0.1
 #  json_serializable: ^2.1.0y
 #  path: ^1.4.1
 
 dev_dependencies:
-  pedantic: ^1.0.0
-  test: ^1.0.0
+  pedantic: ^1.11.0
+  test: ^1.16.8
 #  test_coverage: ^0.2.0
diff --git a/test/poly_test.dart b/test/poly_test.dart
index 5b3bd25..11d630b 100644
--- a/test/poly_test.dart
+++ b/test/poly_test.dart
@@ -1,10 +1,10 @@
 import 'package:poly/poly.dart';
 
-import "package:test/test.dart";
+import 'package:test/test.dart';
 
 void main() {
-  group("Simple Poly test: ", (){
-    List<Point<num>> l = [
+  group('Simple Poly test: ', (){
+    var l = <Point<num>>[
       Point(18.4851825, 73.8498851),
       Point(18.4849214, 73.8498675),
       Point(18.4855965, 73.8520493),
@@ -12,8 +12,8 @@ void main() {
       Point(18.4857828, 73.8500299),
       Point(18.4851825, 73.8498851)
     ];
-    Polygon testPolygon = Polygon(l);
-    Polygon copyOfFirstPolygon = Polygon([
+    var testPolygon = Polygon(l);
+    var copyOfFirstPolygon = Polygon([
       Point(18.4851825, 73.8498851),
       Point(18.4849214, 73.8498675),
       Point(18.4855965, 73.8520493),
@@ -21,165 +21,165 @@ void main() {
       Point(18.4857828, 73.8500299),
       Point(18.4851825, 73.8498851)
     ]);
-    Point in1 = Point(18.48569, 73.85067);
-    test("`hasSamePoint()`",(){
-      bool areTwoSame = testPolygon.hasSamePoints(copyOfFirstPolygon);
+    var in1 = Point(18.48569, 73.85067);
+    test('`hasSamePoint()`',(){
+      bool? areTwoSame = testPolygon.hasSamePoints(copyOfFirstPolygon);
       expect(areTwoSame,equals(true));
     });
-    test("`isPointInside` ",(){
-      bool isIn1InsideTestPolygon = testPolygon.isPointInside(in1);
+    test('`isPointInside` ',(){
+      var isIn1InsideTestPolygon = testPolygon.isPointInside(in1);
       expect(isIn1InsideTestPolygon,equals(true));
     });
-    test("`isPointInside` ",(){
-      bool polygonContain = copyOfFirstPolygon.contains(18.48569, 73.85067);
+    test('`isPointInside` ',(){
+      var polygonContain = copyOfFirstPolygon.contains(18.48569, 73.85067);
       expect(polygonContain,equals(true));
     });
-    test(" areAllPointsInsidePolygon_ListPoint : true ", () {
-      bool areAllInside = testPolygon.areAllPointsInsidePolygon_ListPoint(l);
+    test(' areAllPointsInsidePolygon_ListPoint : true ', () {
+      var areAllInside = testPolygon.areAllPointsInsidePolygon_ListPoint(l);
       expect(areAllInside,equals(true));
     });
-    test(" areAllPointsInsidePolygon_ListPoint : false  ", () {
-      List<Point<num>> notInsidePoints = []..addAll(l)..addAll([Point(75, 90)]);
-      bool areAllInside = testPolygon.areAllPointsInsidePolygon_ListPoint(notInsidePoints);
+    test(' areAllPointsInsidePolygon_ListPoint : false  ', () {
+      var notInsidePoints = <Point<num>>[...l, Point(75, 90)];
+      var areAllInside = testPolygon.areAllPointsInsidePolygon_ListPoint(notInsidePoints);
       expect(areAllInside,equals(false));
     });
-    test(" getList_IsListOfPointInside  ", () {
-      List<Point<num>> notInsidePoints = []..addAll(l)..addAll([Point(75, 90)]);
-      List<bool> statusOfPoints = testPolygon.getList_IsListOfPointInside(notInsidePoints);
+    test(' getList_IsListOfPointInside  ', () {
+      var notInsidePoints = <Point<num>>[...l, Point(75, 90)];
+      var statusOfPoints = testPolygon.getList_IsListOfPointInside(notInsidePoints);
       expect(statusOfPoints,equals([true, true, true, true, true, true, false]));
     });
   });
 
-  group("Dynamic to num: ", (){
-    List correctDynamicList = [1, 2, 'a', 3];
-    List listOf = [
+  group('Dynamic to num: ', (){
+    var correctDynamicList = [1, 2, 'a', 3];
+    var listOf = [
       [1, true],
       [2, 'Remove me'],
       [3, 4],
       [5, 6],
       [7, 8]
     ];
-    group("toListNum: ",(){
-      group("Old List: ",(){
-        test("Type",(){
+    group('toListNum: ',(){
+      group('Old List: ',(){
+        test('Type',(){
           var oldType = correctDynamicList.runtimeType.toString();
-          expect(oldType,equals("List<dynamic>"));
+          expect(oldType,equals('List<dynamic>'));
         });
-        test("Length",(){
+        test('Length',(){
           var oldLength = correctDynamicList.length;
           expect(oldLength,equals(4));
         });
       });
-      group("without any optional parameters:",() {
-        List<num> lWithoutAnyOptional = toListNum(correctDynamicList);
-        test("Type", () {
+      group('without any optional parameters:',() {
+        var lWithoutAnyOptional = toListNum(correctDynamicList);
+        test('Type', () {
           var type = lWithoutAnyOptional.runtimeType.toString();
-          expect(type, equals("List<num>"));
+          expect(type, equals('List<num>'));
         });
-        test("Length", () {
+        test('Length', () {
           var length = lWithoutAnyOptional.length;
           expect(length, equals(2));
         });
-        test("Value", () {
+        test('Value', () {
           expect(lWithoutAnyOptional, equals([1, 2]));
         });
       });
-        group("with `replaceWithZero: true` and `sizeTwo: false`:",(){
-          List<num> lSizeNotTwo_Zero =
+        group('with `replaceWithZero: true` and `sizeTwo: false`:',(){
+          var lSizeNotTwo_Zero =
           toListNum(correctDynamicList, replaceWithZero: true, sizeTwo: false);
-          test("Type",(){
+          test('Type',(){
             var type = lSizeNotTwo_Zero.runtimeType.toString();
-            expect(type,equals("List<num>"));
+            expect(type,equals('List<num>'));
           });
-          test("Length",(){
+          test('Length',(){
             var length = lSizeNotTwo_Zero.length;
             expect(length,equals(4));
           });
-          test("Value",(){
+          test('Value',(){
             expect(lSizeNotTwo_Zero,equals([1,2,0,3]));
           });
         });
-      group("with `sizeTwo: false`:",(){
-        List<num> lSizeNotTwo = toListNum(correctDynamicList, sizeTwo: false);
-        test("Type",(){
+      group('with `sizeTwo: false`:',(){
+        var lSizeNotTwo = toListNum(correctDynamicList, sizeTwo: false);
+        test('Type',(){
           var type = lSizeNotTwo.runtimeType.toString();
-          expect(type,equals("List<num>"));
+          expect(type,equals('List<num>'));
         });
-        test("Length",(){
+        test('Length',(){
           var length = lSizeNotTwo.length;
           expect(length,equals(3));
         });
-        test("Value",(){
+        test('Value',(){
           expect(lSizeNotTwo,equals([1,2,3]));
         });
       });
     });//toListnum
 
-    group("toListListNum: ",(){
-        group("Old List: ",(){
-          test("Type",(){
+    group('toListListNum: ',(){
+        group('Old List: ',(){
+          test('Type',(){
             var oldType = listOf.runtimeType.toString();
-            expect(oldType,equals("List<dynamic>"));
+            expect(oldType,equals('List<dynamic>'));
           });
-          test("Length",(){
+          test('Length',(){
             var oldLength = listOf.length;
             expect(oldLength,equals(5));
           });
         });
-      group("without any optional parameters: ",() {
-        List<List<num>> m = toListListNum(listOf);
-        test("Type", () {
+      group('without any optional parameters: ',() {
+        List<List<num?>> m = toListListNum(listOf);
+        test('Type', () {
           var type = m.runtimeType.toString();
-          expect(type, equals("List<List<num>>"));
+          expect(type, equals('List<List<num>>'));
         });
-        test("Length", () {
+        test('Length', () {
           var length = m.length;
           expect(length, equals(3));
         });
-        test("Value", () {
+        test('Value', () {
           expect(m, equals([[3, 4], [5, 6], [7, 8]]));
         });
       });
-      group("with `swapXAndY: true`: ",(){
-        List<List<num>> mSwap = toListListNum(listOf, swapXAndY: true);
-        test("Type",(){
+      group('with `swapXAndY: true`: ',(){
+        List<List<num?>> mSwap = toListListNum(listOf, swapXAndY: true);
+        test('Type',(){
           var type = mSwap.runtimeType.toString();
-          expect(type,equals("List<List<num>>"));
+          expect(type,equals('List<List<num>>'));
         });
-        test("Length",(){
+        test('Length',(){
           var length = mSwap.length;
           expect(length,equals(3));
         });
-        test("Value",(){
+        test('Value',(){
           expect(mSwap,equals([[4, 3], [6, 5], [8, 7]]));
         });
       });
-      group("with `replaceWithZero: true`:",(){
-        List<List<num>> mZero = toListListNum(listOf, replaceWithZero: true);
-        test("Type",(){
+      group('with `replaceWithZero: true`:',(){
+        List<List<num?>> mZero = toListListNum(listOf, replaceWithZero: true);
+        test('Type',(){
           var type = mZero.runtimeType.toString();
-          expect(type,equals("List<List<num>>"));
+          expect(type,equals('List<List<num>>'));
         });
-        test("Length",(){
+        test('Length',(){
           var length = mZero.length;
           expect(length,equals(5));
         });
-        test("Value",(){
+        test('Value',(){
           expect(mZero,equals([[1, 0], [2, 0], [3, 4], [5, 6], [7, 8]]));
         });
       });
-        group("with `replaceWithZero: true` and `swapXAndY: true`: ",(){
-          List<List<num>> mZeroSwap =
+        group('with `replaceWithZero: true` and `swapXAndY: true`: ',(){
+          List<List<num?>> mZeroSwap =
           toListListNum(listOf, replaceWithZero: true, swapXAndY: true);
-          test("Type",(){
+          test('Type',(){
             var type = mZeroSwap.runtimeType.toString();
-            expect(type,equals("List<List<num>>"));
+            expect(type,equals('List<List<num>>'));
           });
-          test("Length",(){
+          test('Length',(){
             var length = mZeroSwap.length;
             expect(length,equals(5));
           });
-          test("Value",(){
+          test('Value',(){
             expect(mZeroSwap,equals([[0, 1], [0, 2], [4, 3], [6, 5], [8, 7]]));
           });
         });