code: def _lookup_identity_names(self):
          
          id_batch_size = 100
  
          # fetch in batches of 100, store in a dict
          ac = get_auth_client()
          self._resolved_map = {}
          for i in range(0, len(self.identity_ids), id_batch_size):
              chunk = self.identity_ids[i : i + id_batch_size]
              resolved_result = ac.get_identities(ids=chunk)
              for x in resolved_result["identities"]:
                  self._resolved_map[x["id"]] = x["username"]
docs: Batch resolve identities to usernames.
          Returns a dict mapping IDs to Usernames