public void SutEvaluatesAsSumOfInputs(IEnumerable<double> inputs, DoubleSumFunction sut)
        {
            var result = sut.Evaluate(inputs);

            var expected = inputs.Sum();
            Assert.Equal<double>(expected, result);
        }
 public void SutIsEvaluatable(DoubleSumFunction sut)
 {
     Assert.IsAssignableFrom<ITransformingFunction<IEnumerable<double>, double>>(sut);
 }