Remove base class in favour of extensions

.gitignore

@@ -1,4 +1,3 @@
 *.lock
 .packages
 .dart_tool
-example/lib/*.g.dart

.travis.yml

@@ -1,5 +1,5 @@
 language: dart
 dart:
 - stable
-- 2.5.2
+- 2.7.0
 script: ${TRAVIS_BUILD_DIR}/scripts/check-all --prepare

example/lib/data_classes.dart

@@ -72,13 +72,13 @@ void main() {
 }
 
 @DataClass()
-mixin Container<T> on _ContainerBase<T> {
+mixin Container<T> {
   String get id;
   T get payload;
 }
 
 @SumType()
-mixin Either<A, B> on _EitherBase<A, B> {
+mixin Either<A, B> {
   A get _left;
   B get _right;
 }
@@ -88,7 +88,7 @@ void foo(Either<String, int> x) {
 }
 
 @DataClass()
-mixin User on _UserBase {
+mixin User {
   String get name;
   Optional<int> get age;
   KtList<User> get friends;
@@ -106,7 +106,7 @@ mixin User on _UserBase {
 mixin NullaryType {}
 
 @DataClass(toString: false)
-mixin CustomToString on _CustomToStringBase {
+mixin CustomToString {
   String get foo;
   String get bar;
 
@@ -116,7 +116,7 @@ mixin CustomToString on _CustomToStringBase {
 }
 
 @DataClass(eqHashCode: false)
-mixin CustomEq on _CustomEqBase {
+mixin CustomEq {
   String get foo;
   String get bar;
 
@@ -129,148 +129,3 @@ mixin CustomEq on _CustomEqBase {
     return 42;
   }
 }
-
-/*
-// START generated code
-abstract class UserFactory {
-  static User make({
-    @required String name,
-    int age,
-    @required KtList<User> friends,
-    @required ty.Address address,
-    ty.Address workAddress,
-    @required KtList<ty.Address> friendsAddresses,
-  }) {
-    return _User.make(
-      name: name,
-      age: Optional.of(age),
-      friends: friends,
-      address: address,
-      workAddress: Optional.of(workAddress),
-      friendsAddresses: friendsAddresses,
-    );
-  }
-}
-
-abstract class _UserBase {
-  _User copyWith(
-      {String name,
-      Optional<int> age,
-      KtList<User> friends,
-      ty.Address address,
-      Optional<ty.Address> workAddress,
-      KtList<ty.Address> friendsAddresses});
-}
-
-@immutable
-class _User extends _UserBase with User {
-  final String name;
-  final Optional<int> age;
-  final KtList<User> friends;
-  final ty.Address address;
-  final Optional<ty.Address> workAddress;
-  final KtList<ty.Address> friendsAddresses;
-
-  // We cannot have a const constructor because of https://github.com/dart-lang/sdk/issues/37810
-  _User.make({
-    @required this.name,
-    @required this.age,
-    @required this.friends,
-    @required this.address,
-    @required this.workAddress,
-    @required this.friendsAddresses,
-  })  : assert(name != null),
-        assert(age != null),
-        assert(friends != null),
-        assert(address != null),
-        assert(workAddress != null),
-        assert(friendsAddresses != null);
-
-  _User copyWith(
-      {String name,
-      Optional<int> age,
-      KtList<User> friends,
-      ty.Address address,
-      Optional<ty.Address> workAddress,
-      KtList<ty.Address> friendsAddresses}) {
-    return _User.make(
-      name: name ?? this.name,
-      age: age ?? this.age,
-      friends: friends ?? this.friends,
-      address: address ?? this.address,
-      workAddress: workAddress ?? this.workAddress,
-      friendsAddresses: friendsAddresses ?? this.friendsAddresses,
-    );
-  }
-
-  bool operator ==(Object other) {
-    if (identical(this, other)) {
-      return true;
-    }
-    return (other is _User &&
-        this.runtimeType == other.runtimeType &&
-        this.name == other.name &&
-        this.age == other.age &&
-        this.friends == other.friends &&
-        this.address == other.address &&
-        this.workAddress == other.workAddress &&
-        this.friendsAddresses == other.friendsAddresses);
-  }
-
-  int get hashCode {
-    var result = 17;
-    result = 37 * result + this.name.hashCode;
-    result = 37 * result + this.age.hashCode;
-    result = 37 * result + this.friends.hashCode;
-    result = 37 * result + this.address.hashCode;
-    result = 37 * result + this.workAddress.hashCode;
-    result = 37 * result + this.friendsAddresses.hashCode;
-    return result;
-  }
-
-  String toString() {
-    return "User(name: ${this.name}, age: ${this.age}, friends: ${this.friends}, address: ${this.address}, workAddress: ${this.workAddress}, friendsAddresses: ${this.friendsAddresses})";
-  }
-}
-
-/// This data class has been generated from NullaryType
-abstract class NullaryTypeFactory {
-  static NullaryType make() {
-    return _NullaryType.make();
-  }
-}
-
-abstract class _NullaryTypeBase {
-  _NullaryType copyWith();
-}
-
-@immutable
-class _NullaryType extends _NullaryTypeBase with NullaryType {
-  // We cannot have a const constructor because of https://github.com/dart-lang/sdk/issues/37810
-  _NullaryType.make();
-
-  _NullaryType copyWith() {
-    return _NullaryType.make();
-  }
-
-  bool operator ==(Object other) {
-    if (identical(this, other)) {
-      return true;
-    }
-    return (other is _NullaryType &&
-        this.runtimeType == other.runtimeType &&
-        true);
-  }
-
-  int get hashCode {
-    var result = 17;
-
-    return result;
-  }
-
-  String toString() {
-    return "NullaryType()";
-  }
-}
-// END generated code
-*/