### Question:
Gcd extends Operator { @Override public Generic numeric() { final Generic first = parameters[0]; final Generic second = parameters[1]; try { final JsclInteger firstInt = first.integerValue(); final JsclInteger secondInt = second.integerValue(); return firstInt.gcd(secondInt); } catch (NotIntegerException e) { } return first.gcd(second); } Gcd(@Nonnull Generic first, @Nonnull Generic second);  Gcd(); private  Gcd(@Nonnull Generic[] parameters); @Nonnull @Override Operator newInstance(@Nonnull Generic[] parameters); @Override int getMinParameters(); @Override Generic selfExpand(); @Override Generic numeric(); @Nonnull @Override Gcd newInstance();  }### Answer:
@Test public void testNumeric() throws Exception { JsclMathEngine mathEngine = JsclMathEngine.getInstance(); }