/// <summary> /// Asynchronously clears the landmark identified by the provided <paramref name="id" />. /// </summary> /// <param name="id">The identifier of the landmark.</param> /// <returns></returns> public async Task ClearLandmark(int id) { var landmark = _dataContext.Landmarks.FirstOrDefault(l => l.Id == id); if (landmark != null) { landmark.Expiry = DateTimeOffset.Now.AddDays(-1); await _dataContext.SaveChangesAsync(); } }