assertion  retraction  graph  subject     predicate        object     datatype    annotation
1          0           graph  DOID:13538  rdfs:subClassOf  DOID:6199  _IRI        
1          0           graph  DOID:8400   rdfs:subClassOf  DOID:6199  _IRI        
1          0           graph  DOID:6199   oio:id           DOID:6199  xsd:string