public void AddRedisQueryStorage_Factory_Is_Null()
        {
            // arrange
            IRequestExecutorBuilder builder = new ServiceCollection().AddGraphQL();

            // act
            void Action() =>
            HotChocolateRedisPersistedQueriesRequestExecutorBuilderExtensions
            .AddRedisQueryStorage(builder, default(Func <IServiceProvider, IDatabase>) !);

            // assert
            Assert.Throws <ArgumentNullException>(Action);
        }