import 'dart:async';

class A {
  void method1() {}
  FutureOr<void> method2() {}
  FutureOr<void> method3() {}
}

class B {
  void method1() {}
  void method2() {}
  FutureOr<void> method3() {}
}

class C implements A, B {
  method1() {}
  method2() {}
  method3() {}
}

main() {}