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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 known(self, node):
 """ resolve type referenced by @xsi:type """

        ref = node.get('type', Namespace.xsins)
        if ref is None:
            return None
        qref = qualify(ref, node, node.namespace())
        query = BlindQuery(qref)
        return query.execute(self.schema)