model.addTest(new FixedPendulumTest(true));
model.addTest(new FreePendulumTest(true));
model.addTest(new Chain());
model.addTest(new RopeTest());
model.addTest(new Pulleys());
model.addTest(new Gears());
model.addTest(new Web());
model.addTest(new Cantilever());
model.addTest(new SliderCrankTest());
// ccd