code: def export(self, source=None):
          uidentities = {}
          uids = api.unique_identities(self.db, source=source)
          for uid in uids:
              enrollments = [rol.to_dict()
                             for rol in api.enrollments(self.db, uuid=uid.uuid)]
              u = uid.to_dict()
              u['identities'].sort(key=lambda x: x['id'])
              uidentities[uid.uuid] = u
              uidentities[uid.uuid]['enrollments'] = enrollments
          blacklist = [mb.excluded for mb in api.blacklist(self.db)]
          obj = {'time': str(datetime.datetime.now()),
                 'source': source,
                 'blacklist': blacklist,
                 'organizations': {},
                 'uidentities': uidentities}
          return json.dumps(obj, default=self._json_encoder,
                            indent=4, separators=(',', ': '),
                            sort_keys=True)