/** Tests the method {@link Operator#operate(Number, Number)}. */ @Test public void testOperate() { // tests ADD Assert.assertEquals(10, Operator.ADD.operate(6, 4)); // tests SUB Assert.assertEquals(8, Operator.SUB.operate(13, 5)); // tests MUL Assert.assertEquals(18, Operator.MUL.operate(2, 9)); // tests DIV Assert.assertEquals(2.5, Operator.DIV.operate(5, 2)); }