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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def this_machine(self, machineid=None):
 """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'). """

        if machineid is None:
            machineid = _id128.get_machine().hex
        else:
            machineid = getattr(machineid, 'hex', machineid)
        self.add_match(_MACHINE_ID=machineid)