imanushin 

Library to simplify runtime checking by using code contracts.

This tool is the bridge from FitNesse host and you test code. Use it to write tests on FitNesse and execute them in .Net

This package is for projects on Microsoft Visual Studio 2015 to have design-time and compile-time warnings. It checks, that all reference parameters in methods and constructors have NotNull/CanBeNull attributes. You have to use Jetbrains.