diff --git a/src/services/NotificationService.ts b/src/services/NotificationService.ts
index 3ecaf58..5b9105d 100644
--- a/src/services/NotificationService.ts
+++ b/src/services/NotificationService.ts
@@ -91,6 +91,15 @@ export class NotificationService {
 
   }
 
+  /**
+   * Check whether the notification is scheduled.
+   * @param deviceId
+   * @param shuttleId
+   * @param stopId
+   */
+  public isNotificationScheduled({ deviceId, shuttleId, stopId }: ScheduledNotificationData) {
+  }
+
   public cancelAllNotifications(deviceId: string) {
 
   }