def start(self, threaded=True):
        """Start the data feed.

        :param threaded: If True, run in a separate thread.
        """
        self.running = True
        if threaded:
            self._thread = Thread(target=self._run)
            self._thread.start()
        else:
            self._run()
Start the data feed.

        :param threaded: If True, run in a separate thread.