Best way to develop in parallel

Hi -

I have MyPossiblyFlawedClass and MyOtherPossibilyFlawedClass.
Both have exactly the same method signatures, constructors,
etc.

They solve a number crunching problem using two different
algorithms and they're being used to discover flaws in the
other. How can I easily switch between the classes? I'm
doing it now with an import mypath.classA/classB statement.

But this is getting a bit out of control. I'm constantly
switching four import statements many times a day.

Thanks for any ideas.
Brian
.