/// <summary>
 /// Returns all settings, cached for 10 min, returns null if no setting found.
 /// </summary>
 /// <returns></returns>
 /// <remarks>
 /// TODO needs to get only settings from meta.
 /// </remarks>
 private async Task <List <Meta> > GetAllSettingsAsync()
 {
     return(await _cache.GetAsync(CACHE_KEY_ALL_SETTINGS, new TimeSpan(0, 10, 0), async() =>
     {
         return await _repo.AllAsync();
     }));
 }