code: @SuppressWarnings("unchecked")
      public HashMap<String, String> getFlattenedMetaData() {
          HashMap<String, String> result = new HashMap<String, String>();
          for (MetaRecord mr : meta) {
              result.putAll((Map<String, String>) mr
                      .get(FieldName.META_PROPERTIES));
          }
          return result;
      }
docs: Return a flattenned key/value map of all available properties from all
  {@link MetaRecord}s
  
  @return