code: def derived_class_implements_method(derived: Type[T1],
                                      base: Type[T2],
                                      method_name: str) -> bool:
      
      derived_method = getattr(derived, method_name, None)
      if derived_method is None:
          return False
      base_method = getattr(base, method_name, None)
      # if six.PY2:
      #     return derived_method.__func__ != base_method.__func__
      # else:
      #     return derived_method is not base_method
      return derived_method is not base_method
docs: Does a derived class implement a method (and not just inherit a base
      class's version)?
  
      Args:
          derived: a derived class
          base: a base class
          method_name: the name of a method
  
      Returns:
          whether the derived class method is (a) present, and (b) different to
          the base class's version of the same method
  
      Note: if C derives from B derives from A, then a check on C versus A will
      succeed if C implements the method, or if C inherits it from B but B has
      re-implemented it compared to A.