def reset_clipboard(self):
        """ Resets the clipboard, so that old elements do not pollute the new selection that is copied into the
            clipboard.

        :return:
        """
        # reset selections
        for state_element_attr in ContainerState.state_element_attrs:
            self.model_copies[state_element_attr] = []

        # reset parent state_id the copied elements are taken from
        self.copy_parent_state_id = None

        self.reset_clipboard_mapping_dicts()