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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):
 """ Nothing that requires any overwrite. """

        all_conns = chain(
            self._available_connections.values(),
            self._in_use_connections.values(),
        )

        for node_connections in all_conns:
            for connection in node_connections:
                connection.disconnect()