code: public EntityBuilder addLinks(List<Link> links) {
      	if(links == null) {
      		throw new IllegalArgumentException("links cannot be null.");
      	}
          for (Link link : links) {
              addLink(link);
          }
          return this;
      }
docs: Adds list of links to the entity to be built. Links are optional according to the Siren specification, however
  an entity should always have a 'self' link to be considered HATEAOS compliant.
  @param links cannot be <code>null</code>, may be empty.
  @return <code>this</code> builder, never <code>null</code>.