The following DataNodes have no identifier: 1
http://classic.wikipathways.org/instance/WP3122_r105919 http://rdf.wikipathways.org/Pathway/WP3122_r105919/DataNode/ebd00 (RTK)
More details at https://www.wikipathways.org/WikiPathwaysCurator/DataNodesTests/dataNodesWithoutIdentifier