public void AddPreprocessor_Should_Succeed()
        {
            var preprocessor1 = new TestReturnNullPreprocessor();
            var builder       = new HubConfigurationBuilder <TestRoutable>();

            HubConfigurationBuilderExtensions.AddPreprocessor <TestRoutable>(builder, preprocessor1);
            builder.Preprocessors.Should().Contain(preprocessor1);
        }
        public void AddPreprocessorNull_ShouldThrow_ArgumentNullException()
        {
            var builder = new HubConfigurationBuilder <TestRoutable>();

            Assert.Throws <ArgumentNullException>(() => HubConfigurationBuilderExtensions.AddPreprocessor(builder, null));
        }