class A {
  String get call => "My name is A";
}

class B {
  String Function() get call => () => "My name is B";
}

extension on int {
  String get call => "My name is int";
}

extension on num {
  String get call => "My name is num";
}

extension on String {
  String Function() get call => () => "My name is String";
}

main() {}

var topLevel1 = 1(10);

var topLevel2 = 1("10");

var topLevel3 = 1.0(10);

var topLevel4 = 1.0("10");

A a = new A();

var topLevel5 = a(2);

B b = new B();

var topLevel6 = a(2, "3");

errors() {}