code: def this_machine(self, machineid=None):
          
          if machineid is None:
              machineid = _id128.get_machine().hex
          else:
              machineid = getattr(machineid, 'hex', machineid)
          self.add_match(_MACHINE_ID=machineid)
docs: Add match for _MACHINE_ID equal to the ID of this machine.
  
          If specified, machineid should be either a UUID or a 32 digit hex
          number.
  
          Equivalent to add_match(_MACHINE_ID='machineid').