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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 path(self) -> Tuple[InstanceKey]: """Return the list of keys on the path from root to the receiver."""

        res = []
        inst: InstanceNode = self
        while inst.parinst:
            res.insert(0, inst._key)
            inst = inst.parinst
        return tuple(res)