The following DataNodes have no identifier: 3
http://classic.wikipathways.org/instance/WP3620_r118336 http://rdf.wikipathways.org/Pathway/WP3620_r118336/DataNode/b6ec2 (I 3-(2'-Rha)Glc-7-Rha)
http://classic.wikipathways.org/instance/WP3620_r118336 http://rdf.wikipathways.org/Pathway/WP3620_r118336/DataNode/a4336 (Luteolin 5,7-diglucoside)
http://classic.wikipathways.org/instance/WP3620_r118336 http://rdf.wikipathways.org/Pathway/WP3620_r118336/DataNode/f2821 (epicatechin heptamer)
More details at https://www.wikipathways.org/WikiPathwaysCurator/DataNodesTests/dataNodesWithoutIdentifier