What was the hardest to program this year in Java?

[FRC4ME]

Oh, and I forgot to mention: finding and fixing bugs in WPI's code.

So far we're overriding three of WPI's classes with our own versions: PWM, because someone forgot to cast two integers to doubles before dividing them; Encoder, because someone divided by 0.25 when they should have divided by four; and DriverStation, because the scaling on the joystick axes is wrong (it goes from -1.0 to 0.9 rather than -1.0 to 1.0 due to the use of two's complement).

Not that I'm complaining; when volunteers write 20,000 lines of code there are bound to be a few errors. In fact, I'm glad WPILib isn't perfect, because then my programming team would have nothing to do after week one.