public async Task <IEnumerable <MediaBundle <Artist> > > GetArtistsAsync(Guid userId, Guid?collectionId, CancellationToken cancellationToken) { if (_memoryCache.TryGetValue(CacheTypes.Artists, out IEnumerable <MediaBundle <Artist> > artists)) { return(artists); } artists = (await _metadataRepository.GetArtistsAsync(userId, collectionId, cancellationToken).ConfigureAwait(false)).ToList(); _memoryCache.Set(CacheTypes.Artists, artists, DefaultMemoryCacheEntryOptions); return(artists); }