ArgumentUtils { public static void checkPositive(long number, final String msg) { if (number < 1) { throw new IllegalArgumentException(msg); } }  static void checkNotNull(final Object reference, final String msg); static void checkPositive(long number, final String msg); static void checkNotEmpty(final String str, final String msg);  }
@Test(expected = IllegalArgumentException.class) public void checkPositive() { ArgumentUtils.checkPositive(-1, "positive"); }
@Test(expected = IllegalArgumentException.class) public void checkPositiveZero() { ArgumentUtils.checkPositive(0, "positive"); }