docs: public static Rel getRelFor(String rel, LinkDiscoverers discoverers) {
  
  		Assert.hasText(rel, "Relation name must not be null!");
  		Assert.notNull(discoverers, "LinkDiscoverers must not be null!");
  
  		if (rel.startsWith("$")) {
  			return new JsonPathRel(rel);
  		}
  
  		return new LinkDiscovererRel(rel, discoverers);
  	}