This is an implementation of 'Continuations' for Java created as an exercise. It is not a reliable library and should not be used for production purposes. Don't blame me if you try and it all goes wrong, but do drop me a line with all the gory details!
A short write up is online at paperstack.com.
For a complete example usage see the test case
If you submit this as your homework as a solution to a Fibonacci exercise then I dare say that you will get everything you deserve.