src/vs/platform/terminal/node/ptyHostService.ts/PtyHostService/_clearHeartbeatTimeouts
class PtyHostService:	private _clearHeartbeatTimeouts() {
		if (this._heartbeatFirstTimeout) {
			clearTimeout(this._heartbeatFirstTimeout);
			this._heartbeatFirstTimeout = undefined;
		}
		if (this._heartbeatSecondTimeout) {
			clearTimeout(this._heartbeatSecondTimeout);
			this._heartbeatSecondTimeout = undefined;
		}
	}