docs: def guest_softstop(self, userid, **kwargs):
          """Issue a shutdown command to shutdown the OS in a virtual
          machine and then log the virtual machine off z/VM..
  
          :param str userid: the id of the virtual machine to be power off
          :param dict kwargs:
                 - timeout=<value>:
                   Integer, time to wait for vm to be deactivate, the
                   recommended value is 300
                 - poll_interval=<value>
                   Integer, how often to signal guest while waiting for it
                   to be deactivate, the recommended value is 20
  
          :returns: None
          """
  
          action = "soft stop guest '%s'" % userid
          with zvmutils.log_and_reraise_sdkbase_error(action):
              self._vmops.guest_softstop(userid, **kwargs)