code: def _is_default_hook(default_hook, hook):
      
      if not hasattr(default_hook, '__call__'):
        raise TypeError('Default hooks for ndb.model.Model must be callable')
      if not hasattr(hook, '__call__'):
        raise TypeError('Hooks must be callable')
      return default_hook.im_func is hook.im_func
docs: Checks whether a specific hook is in its default state.
  
      Args:
        cls: A ndb.model.Model class.
        default_hook: Callable specified by ndb internally (do not override).
        hook: The hook defined by a model class using _post_*_hook.
  
      Raises:
        TypeError if either the default hook or the tested hook are not callable.