// Vocabulary data source contains our normal data sources plus
// the configuration model, so that we can read labels etc from
// the configuration file
DataSource vocabularyDataSource = new MergeDataSource(
new ModelDataSource(getModel()), getDataSource());
vocabularyStore.setDataSource(vocabularyDataSource);
vocabularyStore.setDefaultLanguage(getDefaultLanguage());
// Sanity check to spot typical configuration problem
if (dataSource.getIndex().isEmpty()) {