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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:
 async def stop(self):
 """Safely shut down this interface"""

        await self._command_task.future_command(['_set_mode', 0, 0])  # Disable advertising
        await self._cleanup_old_connections()

        self._command_task.stop()
        self._stream.stop()
        self._serial_port.close()

        await super(BLED112Server, self).stop()