'Returns a list of (related-m2m-object, model) pairs. Similar to
get_fields_with_model().'

def get_all_related_m2m_objects_with_model(self):

    try:
        cache = self._related_many_to_many_cache
    except AttributeError:
        cache = self._fill_related_many_to_many_cache()
    return list(six.iteritems(cache))
