docs: public static Specification<JpaTarget> hasTag(final Long tagId) {
  
          return (targetRoot, query, cb) -> {
              final SetJoin<JpaTarget, JpaTargetTag> tags = targetRoot.join(JpaTarget_.tags, JoinType.LEFT);
              return cb.equal(tags.get(JpaTargetTag_.id), tagId);
          };
      }