Assertion { public static void negative(long number, String name) { if (number >= 0) { throw new InvalidArgumentException(name + " should be negative"); } }  static void notNull(T argument, String format, Object... args); static void notNullOrEmpty(String argument, String name); static void negative(long number, String name); static void positive(long number, String name); static void nonNegative(long number, String name); static void nonPositive(long number, String name);  }
@Test(expected = InvalidArgumentException.class) public void negative_withZero() throws Exception { Assertion.negative(0, "number"); }
@Test(expected = InvalidArgumentException.class) public void negative_withPositive() throws Exception { Assertion.negative(1, "number"); }
@Test public void negative_ok() throws Exception { Assertion.negative(-1, "number"); }