code: def reserve(self, timeout: Optional[int] = None) -> Job:
          
          if timeout is None:
              cmd = b'reserve'
          else:
              cmd = b'reserve-with-timeout %d' % timeout
          return self._job_cmd(cmd, b'RESERVED')
docs: Reserves a job from a tube on the watch list, giving this client
          exclusive access to it for the TTR. Returns the reserved job.
  
          This blocks until a job is reserved unless a ``timeout`` is given,
          which will raise a :class:`TimedOutError <greenstalk.TimedOutError>` if
          a job cannot be reserved within that time.
  
          :param timeout: The maximum number of seconds to wait.