code: def m2m_changed_entity_signal_handler(sender, instance, action, **kwargs):
      
      if action == 'post_add' or action == 'post_remove' or action == 'post_clear':
          save_entity_signal_handler(sender, instance, **kwargs)
docs: Defines a signal handler for a manytomany changed signal. Only listens for the
      post actions so that entities are synced once (rather than twice for a pre and post action).