code: public static <T extends ModifierReviewable.OfAbstraction> ElementMatcher.Junction<T> isAbstract() {
          return new ModifierMatcher<T>(ModifierMatcher.Mode.ABSTRACT);
      }
docs: Matches a {@link ModifierReviewable.OfAbstraction} that is {@code abstract}.
  
  @param <T> The type of the matched object.
  @return A matcher for a {@code abstract} modifier reviewable.