docs: def guest_nic_couple_to_vswitch(self, userid, nic_vdev,
                                      vswitch_name, active=False):
          """ Couple nic device to specified vswitch.
  
          :param str userid: the user's name who owns the nic
          :param str nic_vdev: nic device number, 1- to 4- hexadecimal digits
          :param str vswitch_name: the name of the vswitch
          :param bool active: whether make the change on active guest system
          """
          self._networkops.couple_nic_to_vswitch(userid, nic_vdev,
                                                 vswitch_name, active=active)