code: def _tcp_socket(self):
          
          sock = iostream.IOStream(socket.socket(
                      socket.AF_INET, socket.SOCK_STREAM, socket.IPPROTO_TCP))
          sock.connect(self._address, self._tcp_on_connected)
          sock.set_close_callback(self._tcp_on_closed)
          return sock
docs: Connect to statsd via TCP and return the IOStream handle.
          :rtype: iostream.IOStream