abstract class A1 implements Enum {
  int get index => 0;
  bool operator ==(Object other) => true;
  int get hashCode => 1;
}

mixin M1 implements Enum {
  int get index => 0;
  bool operator ==(Object other) => true;
  int get hashCode => 1;
}

abstract class A2 implements Enum {
  void set index(String value) {}
  void set hashCode(double value) {}
}

mixin M2 implements Enum {
  void set index(String value) {}
  void set hashCode(double value) {}
}

abstract class A3 implements Enum {
  int get index;
  bool operator ==(Object other);
  int get HashCode;
}

mixin M3 implements Enum {
  int get index;
  bool operator ==(Object other);
  int get HashCode;
}

abstract class A4 implements Enum {
  int index = 0;
  int hashCode = 1;
}

mixin M4 implements Enum {
  int index = 0;
  int hashCode = 1;
}

abstract class A5 implements Enum {
  int foo = 0, bar = 1, index = 2, hashCode = 3;
}

mixin M5 implements Enum {
  int foo = 0, bar = 1, index = 2, hashCode = 3;
}
main() {}