code: public static void withLink(Representation representation, String rel, String href, Optional<Predicate<ReadableRepresentation>> predicate, Optional<String> name, Optional<String> title, Optional<String> hreflang, Optional<String> profile) {
          if (predicate.or(Predicates.<ReadableRepresentation>alwaysTrue()).apply(representation)) {
              representation.withLink(rel, href, name.orNull(), title.orNull(), hreflang.orNull(), profile.orNull());
          }
      }
docs: Add a link to this resource
  
  @param rel
  @param href The target href for the link, relative to the href of this resource.