text: class C1:
      def foo(self, x):
          return self
  
  
  class C2:
      def foo(self, x, y):
          return self
  
  
  def f():
      """
      :rtype: C1 | C2
      """
      pass
  
  
  f().foo()  # XXX: Ignore this false negative as for now
  f().foo(1)
  f().foo(1, 2)
  f().foo(1, 2, 3)  # XXX: Ignore this false negative as well
  