The raises matcher

raises.java

public static Matcher<Callable<?>> raises(Matcher<? super Throwable> sub) {
    return new FeatureMatcher<Callable<?>, Throwable>(sub, "thrown exception", "thrown exception") {
        @Override
        protected Throwable featureValueOf(Callable<?> thing) {
            try {
                thing.call();
            } catch (Throwable e) {
                return e;
            }
            return null;
        }
    };
}