The following DataNodes have no identifier: 1
http://classic.wikipathways.org/instance/WP3941_r123242 http://rdf.wikipathways.org/Pathway/WP3941_r123242/DataNode/c79bb (Cyct)
More details at https://www.wikipathways.org/WikiPathwaysCurator/DataNodesTests/dataNodesWithoutIdentifier