unit testing - How to mock/stub a Java object in C# code? -

My C # code is using the class written in Java (IKVM). Java class provides 2 ways which I am calling in my C # code:

1. GetInstance () - This is just an example of that Java class.
2. GetSet () - gives a network. Decide that I was repeated to do some processing.

We use NUINIT and NMK and I'm relatively new to joke / hustle, so I am quite confused about how the unit test case for this piece of C # code Write which will return a Java object, etc.

Any help / pointers will be highly appreciated. Thank you.