Address already in use with python unit test

WARNING:thrift.transport.sslcompat:ipaddress module is unavailable WARNING:thrift.transport.sslcompat:backports.ssl_match_hostname is unavailable .skipping test_client_cert .......PROTOCOL_SSLv3 is not available PROTOCOL_SSLv2 is not available .EException in thread __enter__: Traceback (most recent call last): File "/Users/jun/.pyenv/versions/2.7.15/lib/python2.7/threading.py", line 801, in __bootstrap_inner self.run() File "test/test_sslsocket.py", line 64, in run self._server.listen() File "/Users/jun/.pyenv/versions/thrift-py2/lib/python2.7/site-packages/thrift/transport/TSocket.py", line 185, in listen self.handle.bind(res[4]) File "/Users/jun/.pyenv/versions/2.7.15/lib/python2.7/socket.py", line 228, in meth return getattr(self._sock,name)(*args) error: [Errno 48] Address already in use