@SafeVarargs
    public static void setExceptionsToIgnore(Class<? extends Throwable>... ignoreClasses) {
        checkNotNull(ignoreClasses);
        Tracer.ignoreClasses = ignoreClasses;
    }
@Test(expected = IllegalArgumentException.class)
    public void testNull2() {
        Tracer.setExceptionsToIgnore(IgnoreException.class, null);
    }