<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def filter(self, destination_object=None, source_object=None, **kwargs):
 """ See ``QuerySet.filter`` for full documentation This adds support for ``destination_object`` and ``source_object`` as kwargs. This converts those objects into the values necessary to handle the ``GenericForeignKey`` fields. """

        if destination_object:
            kwargs.update({
                "destination_id": destination_object.pk,
                "destination_type": get_for_model(destination_object),
            })
        if source_object:
            kwargs.update({
                "source_id": source_object.pk,
                "source_type": get_for_model(source_object),
            })
        return super(RelatedContentQuerySet, self).filter(**kwargs)