Get positive relation labels for ``cid``.

        If ``min_strength`` is set, will restrict results to labels
        with a ``rel_strength`` greater or equal to the provided
        ``RelationStrength`` value. Note: ``min_strength`` should be of
        type ``RelationStrength``.

def get_related(self, content_id, min_strength=None):
        '''Get positive relation labels for ``cid``.

        If ``min_strength`` is set, will restrict results to labels
        with a ``rel_strength`` greater or equal to the provided
        ``RelationStrength`` value. Note: ``min_strength`` should be of
        type ``RelationStrength``.
        '''
        def is_related(label):
            if min_strength is not None:
                return label.rel_strength >= min_strength
            else:
                return label.rel_strength.is_positive

        labels = self.everything(content_id=content_id)
        return ifilter(is_related, labels)