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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 unmarshal_props(self, fp, cls=None, id=None):
 """ Same as unmarshalling an object, except it returns from "get_props_from_doc" """

        if isinstance(fp, str) or isinstance(fp, unicode):
            doc = parseString(fp)
        else:
            doc = parse(fp)
        return self.get_props_from_doc(cls, id, doc)