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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_all(self):
 """ Disconnect all nodes :return: """

        rhs = 'b:' + self.definition['node_class'].__label__
        rel = _rel_helper(lhs='a', rhs=rhs, ident='r', **self.definition)
        q = 'MATCH (a) WHERE id(a)={self} MATCH ' + rel + ' DELETE r'
        self.source.cypher(q)