'Select standard transaction mode. This method sets the channel to use
standard transactions. The client must use this method at least once on
a channel before using the Commit or Rollback methods.
:returns: Method frame from the Tx.Select-ok response
:rtype: `pika.frame.Method` having `method` attribute of type
`spec.Tx.SelectOk`'

def tx_select(self):

    with _CallbackResult(self._MethodFrameCallbackResultArgs) as select_ok_result:
        self._impl.tx_select(select_ok_result.set_value_once)
        self._flush_output(select_ok_result.is_ready)
        return select_ok_result.value.method_frame
