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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_http_server(self, port, host='0.0.0.0', endpoint='/metrics'):
 """ Start an HTTP server for exposing the metrics. This will be an individual Flask application, not the one registered with this class. :param port: the HTTP port to expose the metrics endpoint on :param host: the HTTP host to listen on (default: `0.0.0.0`) :param endpoint: the URL path to expose the endpoint on (default: `/metrics`) """


        if is_running_from_reloader():
            return

        app = Flask('prometheus-flask-exporter-%d' % port)
        self.register_endpoint(endpoint, app)

        def run_app():
            app.run(host=host, port=port)

        thread = threading.Thread(target=run_app)
        thread.setDaemon(True)
        thread.start()