human
I wrote the below code

    def Modified(self):
        'Sets    the    _cached_byte_size_dirty    bit    to    true,\n                and    propagates    this    to    our    listener    iff    this    was    a    state    change.\n                '
        if (not self._cached_byte_size_dirty):
            self._cached_byte_size_dirty = True
            self._listener_for_children.dirty = True
            self._is_present_in_parent = True
            self._listener.Modified()
    cls._Modified = Modified
    cls.SetInParent = Modified

What's a good function header?
assistant
#Here's a good function header.

def _AddPrivateHelperMethods(cls):