public MongoContentRepository(IMongoDatabase database, IAppProvider appProvider, ITextIndex indexer, IJsonSerializer serializer)
        {
            Guard.NotNull(appProvider, nameof(appProvider));
            Guard.NotNull(serializer, nameof(serializer));

            this.appProvider = appProvider;

            converter = new DataConverter(serializer);

            collectionAll       = new MongoContentCollectionAll(database, appProvider, indexer, converter);
            collectionPublished = new MongoContentCollectionPublished(database, appProvider, indexer, converter);
        }