def _AddPrivateHelperMethods(cls):
 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

def _AddPrivateHelperMethods ( cls ) : def Modified ( self ) : 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
adds implementation of private helper methods to cls .