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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 start(self, func=None):
 """Start the roaster control process. This function will kick off the processing thread for the Hottop and register any user-defined callback function. By default, it will not begin collecting any reading information or saving it. In order to do that users, must issue the monitor/record bit via `set_monitor`. :param func: Callback function for Hottop stream data :type func: function :returns: None """

        self._user_callback = func
        if not self._simulate:
            self._process = ControlProcess(self._conn, self._config, self._q,
                                           self._log, callback=self._callback)
        else:
            self._process = MockProcess(self._config, self._q,
                                        self._log, callback=self._callback)
        self._process.start()
        self._roasting = True