IntRangeUtil { public static int requireNegative(int val) { if (val > -1) { throw new IllegalArgumentException(val + IS_NOT_NEGATIVE); } return val; } private  IntRangeUtil(); static int requirePositive(int val); static int requireNegative(int val); static int requireZero(int val); static int requireNonPositive(int val); static int requireNonNegative(int val); static int requireNonZero(int val); static int requireEquals(int val, int otherVal); static int requireNotEquals(int val, int otherVal); static int requireInRange(int val, int first, int lastExclusive); static int requireInRangeClosed(int val, int first, int lastInclusive); static int requirePositive(int val, Function<String, E> exceptionConstructor); static int requireNegative(int val, Function<String, E> exceptionConstructor); static int requireZero(int val, Function<String, E> exceptionConstructor); static int requireNonPositive(int val, Function<String, E> exceptionConstructor); static int requireNonNegative(int val, Function<String, E> exceptionConstructor); static int requireNonZero(int val, Function<String, E> exceptionConstructor); static int requireEquals(int val, int otherVal, Function<String, E> exceptionConstructor); static int requireNotEquals(int val, int otherVal, Function<String, E> exceptionConstructor); static int requireInRange(int val, int first, int lastExclusive, Function<String, E> exceptionConstructor); static int requireInRangeClosed(int val, int first, int lastInclusive, Function<String, E> exceptionConstructor);  }
@Test void requireNegative() { testHelper(IS_NEGATIVE, IntRangeUtil::requireNegative); }
@Test void testRequireNegative() { assertEquals(-1, IntRangeUtil.requireNegative(-1, RuntimeException::new)); }
@Test void testRequireNegative2() { assertThrows(RuntimeException.class, () -> IntRangeUtil.requireNegative(1, RuntimeException::new)); }
@Test void testRequireNegative3() { assertThrows(RuntimeException.class, () -> IntRangeUtil.requireNegative(0, RuntimeException::new)); }