def get_related_coref_relationships(self, content_id, min_strength=None):
        '''Follow coreference relationships to get full related graph.

        :rtype: dict mapping related identifier to list of documents
        coref to that identifier.
        '''
        related_labels = self.rel_label_store.get_related(
            content_id, min_strength=min_strength)
        related_cids = [rel_label.other(content_id)
                        for rel_label in related_labels]
        related_cid_to_idents = {}
        for cid in related_cids:
            conn_labels = self.label_store.directly_connected(cid)
            idents = [label.other(cid) for label in conn_labels]
            related_cid_to_idents[cid] = idents
        return related_cid_to_idents