code: public static <T extends Throwable> Matcher<T> withMessage(String message) {
          return IsThrowable.withMessage(message);
      }
docs: Throwable matcher to be used with {@link #isThrowable(Class, Matcher)}
  @see #isThrowable(Class, Matcher)
  @param message the message
  @param <T> the throwable type
  @return the matcher