def get_pmids(self):
        """Get list of all PMIDs associated with edges in the network."""
        pmids = []
        for ea in self._edge_attributes.values():
            edge_pmids = ea.get('pmids')
            if edge_pmids:
                pmids += edge_pmids
        return list(set(pmids))
Get list of all PMIDs associated with edges in the network.