How to use Guava MapInterfaceTest to test your class

I'm trying to test a class that I've written and which implements the Map from Java using Guava-testlib MapInterfaceTest. When I try and run my MapTest which implements MapInterfaceTest, all the tests fail (almost, 52/56) even though all I did was to call the functions from LinkedHashMap.

Why is this happening? How does the guava interface test actually work and how can I fix my code? The debugger doesn't really help here.