29     close_tx: Mutex<Option<mpsc::Sender<()>>>,  field
38             close_tx: Mutex::new(None),  in new()
49             let close_tx = self.close_tx.lock().await;  in start()  localVariable
50             if close_tx.is_some() {  in start()
55         let (close_tx, mut close_rx) = mpsc::channel(1);  in start()
75             let mut close = self.close_tx.lock().await;  in start()
76             *close = Some(close_tx);  in start()
84         let mut close_tx = self.close_tx.lock().await;  in stop()  localVariable
85         close_tx.take();  in stop()
91         let close_tx = self.close_tx.lock().await;  in is_running()  localVariable
92         close_tx.is_some()  in is_running()