code: private MetadataReferenceDao getMetadataReferenceDao() throws SQLException {
  		if (metadataReferenceDao == null) {
  			metadataReferenceDao = DaoManager.createDao(connectionSource,
  					MetadataReference.class);
  		}
  		return metadataReferenceDao;
  	}
docs: Get or create a Metadata Reference DAO
  
  @return metadata reference dao
  @throws SQLException