### Question:
AssertUtils { public static void isTrue(final boolean expression, final String message, final Object... values) { if (!expression) { throw new IllegalArgumentException(String.format(message, values)); } }  static void assertNotNull(Object instance, String msg); static void assertNull(Object instance, String msg); static void isTrue(final boolean expression, final String message,
                              final Object... values); static void isFalse(final boolean expression, final String message,
                               final Object... values);  }### Answer:
@Test public void testAssertIsTrue() { AssertUtils.isTrue(true, "Exception %s", "error"); try { AssertUtils.isTrue(false, "Exception %s", "error"); } catch (IllegalArgumentException ex) { Assert.assertTrue("Exception error".equals(ex.getMessage())); } }