code: public Map<RDFName, List<DCField>> getMap() {
          Map<RDFName, List<DCField>> map = new HashMap<RDFName, List<DCField>>(15);
  
          if (m_titles != null) map.put(DC.TITLE, m_titles);
          if (m_creators != null) map.put(DC.CREATOR, m_creators);
          if (m_subjects != null) map.put(DC.SUBJECT, m_subjects);
          if (m_descriptions != null) map.put(DC.DESCRIPTION, m_descriptions);
          if (m_publishers != null) map.put(DC.PUBLISHER, m_publishers);
          if (m_contributors != null) map.put(DC.CONTRIBUTOR, m_contributors);
          if (m_dates != null) map.put(DC.DATE, m_dates);
          if (m_types != null) map.put(DC.TYPE, m_types);
          if (m_formats != null) map.put(DC.FORMAT, m_formats);
          if (m_identifiers != null) map.put(DC.IDENTIFIER, m_identifiers);
          if (m_sources != null) map.put(DC.SOURCE, m_sources);
          if (m_languages != null) map.put(DC.LANGUAGE, m_languages);
          if (m_relations != null) map.put(DC.RELATION, m_relations);
          if (m_coverages != null) map.put(DC.COVERAGE, m_coverages);
          if (m_rights != null) map.put(DC.RIGHTS, m_rights);
  
          return map;
      }
docs: Returns a Map with RDFName keys, each value containing List of String
  values for that field.