class MyClass1
def f1(self) => print("1")
class MyClass2
def f2(self) => print("2")
class MyClass3
def f3(self) => print("3")
class MyClass4
def f4(self) => print("4")
def x := MyClass1()
x.f1()
def x := MyClass2()
x.f2()
class MyClass
def x: MyClass3 := MyClass3()
def g() =>
x.f3()
def f(x: MyClass4) =>
x.f4()