def __missing__(self, key):
        if self.default_factory is None:
            raise KeyError(key)
        else:
            ret = self[key] = self.default_factory(name=key)
            return ret
def _on_size_spin_button_value_changed(self, size_spin_button):
    if self._locker.is_unlocked("emit_size_spin_button_value_changed"):
      self._locker.lock("update_spin_button")