model.addTest(new TheoJansen());
// watching...
model.addCategory("Collision Watching");
model.addTest(new VaryingRestitution());
model.addTest(new VaryingFrictionTest());
model.addTest(new ConveyorBelt());
model.addTest(new SphereStack());
model.addTest(new Tumbler());
model.addTest(new PistonTest());
model.addTest(new PyramidTest());