assertion  retraction  graph  subject    predicate        object     datatype    annotation
1          0           graph  DOID:2789  rdfs:subClassOf  DOID:1398  _IRI        
1          0           graph  DOID:883   rdfs:subClassOf  DOID:1398  _IRI        
1          0           graph  DOID:1398  oio:id           DOID:1398  xsd:string