code: def _create_evidence(self, edge_id):
          
          pmids = None
          edge_attr = self._edge_attributes.get(edge_id)
          if edge_attr:
              pmids = edge_attr.get('pmids')
          if not pmids:
              return [Evidence(source_api='ndex',
                               source_id=self._network_info['externalId'],
                               annotations={'edge_id': edge_id})]
          else:
              evidence = []
              for pmid in pmids:
                  evidence.append(
                          Evidence(source_api='ndex',
                                   source_id=self._network_info['externalId'],
                                   pmid=pmid,
                                   annotations={'edge_id': edge_id}))
              return evidence
docs: Create Evidence object for a specific edge/Statement in the network.
  
          Parameters
          ----------
          edge_id : int
              ID of the edge in the underlying NDEx network.