public void UseGraphQLHttpGetSchema_BuilderServices_ServicesIsNull()
        {
            // arrange
            IAppBuilder builder = Mock.Of <IAppBuilder>();

            // act
            Action action =
                () => HttpGetSchemaApplicationBuilderExtensions
                .UseGraphQLHttpGetSchema(builder, null);

            // assert
            Assert.Throws <ArgumentNullException>(action);
        }
        public void UseGraphQLHttpGetSchema_BuilderServices_BuilderIsNull()
        {
            // arrange
            IServiceProvider services = new EmptyServiceProvider();

            // act
            Action action =
                () => HttpGetSchemaApplicationBuilderExtensions
                .UseGraphQLHttpGetSchema(null, services);

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