code: def select(self, cb=None):
          '''
          Set this channel to use transactions.
          '''
          if not self._enabled:
              self._enabled = True
              self.send_frame(MethodFrame(self.channel_id, 90, 10))
              self._select_cb.append(cb)
              self.channel.add_synchronous_cb(self._recv_select_okf select(self, cb=None):
          '''
          Set this channel to use transactions.
          '''
          if not self._enabled:
              self._enabled = True
              self.send_frame(MethodFrame(self.channel_id, 90, 10))
              self._select_cb.append(cb)
              self.channel.add_synchronous_cb(self._recv_select_ok)
docs: Set this channel to use transactions.