private static Set<DcsMetadataRef> getMetadataRefSet(SolrDocument doc, SolrName field) {
    Set<DcsMetadataRef> set = new HashSet<DcsMetadataRef>();

    for (String s : setgetAll(doc, field)) {
      DcsMetadataRef ref = new DcsMetadataRef();

      if (s != null) {
        ref.setRef(s);
      }

      set.add(ref);
    }

    return set;
  }