code: def run(self):
          
          self._listening_sock, self._address = (
              bind_domain_socket(self._address)
              if self._uds_path
              else bind_tcp_socket(self._address))
  
          if self._ssl:
              certfile = os.path.join(os.path.dirname(__file__), 'server.pem')
              self._listening_sock = _ssl.wrap_socket(
                  self._listening_sock,
                  certfile=certfile,
                  server_side=True)
          self._accept_thread = threading.Thread(target=self._accept_loop)
          self._accept_thread.daemon = True
          self._accept_thread.start()
          return self.port
docs: Begin serving. Returns the bound port, or 0 for domain socket.