code: public static Specification<JpaTarget> likeAttributeValue(final String searchText) {
          return (targetRoot, query, cb) -> {
              final String searchTextToLower = searchText.toLowerCase();
              final MapJoin<JpaTarget, String, String> attributeMap = targetRoot.join(JpaTarget_.controllerAttributes,
                      JoinType.LEFT);
              query.distinct(true);
              return cb.like(cb.lower(attributeMap.value()), searchTextToLower);
          };
      }
docs: {@link Specification} for retrieving {@link Target}s by "like attribute
  value".
  
  @param searchText
  to be filtered on
  @return the {@link Target} {@link Specification}