docs: public BundleLinkComponent getLink(String theRelation) {
      org.apache.commons.lang3.Validate.notBlank(theRelation, "theRelation may not be null or empty");
      for (BundleLinkComponent next : getLink()) {
        if (theRelation.equals(next.getRelation())) {
          return next;
        }
      }
      return null;
    }