code: protected HalRepresentation add(final Links links) {
          this.links = this.links != null
                  ? copyOf(this.links).with(links).build()
                  : links.using(this.curies);
          if (embedded != null) {
              embedded = embedded.using(this.curies);
          }
          return this;
      }
docs: Add links to the HalRepresentation.
  <p>
  Links are only added if they are not {@link Link#isEquivalentTo(Link) equivalent}
  to already existing links.
  </p>
  @param links links that are added to this HalRepresentation
  @return this