Tests: AttributeError: 'SrvMonitor' object has no attribute '_seedlist'

 [2019/06/13 16:03:41.542]   test_addition (test_srv_polling.TestSRVPolling) ... ok (0.181s)

 [2019/06/13 16:03:44.662]   test_dns_failures (test_srv_polling.TestSRVPolling) ... ok (3.122s)

 [2019/06/13 16:03:44.699]   test_dns_record_lookup_empty (test_srv_polling.TestSRVPolling) ... Exception in thread pymongo_srv_polling_thread:

 [2019/06/13 16:03:44.699] Traceback (most recent call last):

 [2019/06/13 16:03:44.699]   File "/opt/python/2.7/lib/python2.7/threading.py", line 801, in __bootstrap_inner

 [2019/06/13 16:03:44.699]     self.run()

 [2019/06/13 16:03:44.699]   File "/opt/python/2.7/lib/python2.7/threading.py", line 754, in run

 [2019/06/13 16:03:44.699]     self.__target(*self.__args, **self.__kwargs)

 [2019/06/13 16:03:44.699]   File "/data/mci/02475873e5b4a6a6596e36468c512763/src/pymongo/periodic_executor.py", line 118, in _run

 [2019/06/13 16:03:44.699]     if not self._target():

 [2019/06/13 16:03:44.699]   File "/data/mci/02475873e5b4a6a6596e36468c512763/src/pymongo/monitor.py", line 215, in target

 [2019/06/13 16:03:44.699]     SrvMonitor._run(monitor)

 [2019/06/13 16:03:44.699]   File "/data/mci/02475873e5b4a6a6596e36468c512763/src/pymongo/monitor.py", line 232, in _run

 [2019/06/13 16:03:44.699]     self._seedlist = self._get_seedlist()

 [2019/06/13 16:03:44.699]   File "/data/mci/02475873e5b4a6a6596e36468c512763/src/pymongo/monitor.py", line 254, in _get_seedlist

 [2019/06/13 16:03:44.699]     return self._seedlist

 [2019/06/13 16:03:44.699] AttributeError: 'SrvMonitor' object has no attribute '_seedlist'

 [2019/06/13 16:03:45.865] ok (1.035s)