code: public ListPropertyMetaData getMetaDataOrFail(final List<?> list) {
          final ListPropertyMetaData metaData = listToData.get(list);
          if (metaData == null) {
              throw new ObjectToIdMappingException("Meta data for an unknown property was requested. "
                      + "The clients may no longer be synchron.");
          }
          return metaData;
      }
docs: Returns the meta data for a given {@link List}.
  
  @param list
  The list thats meta data should be returned.
  @return The meta data for the list.