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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 disconnect(self, node):
 """ Disconnect a node :param node: :return: """

        rel = _rel_helper(lhs='a', rhs='b', ident='r', **self.definition)
        q = "MATCH (a), (b) WHERE id(a)={self} and id(b)={them} " \
            "MATCH " + rel + " DELETE r"
        self.source.cypher(q, {'them': node.id})