assertion  retraction  graph  subject    predicate        object     datatype    annotation
1          0           graph  DOID:2706  oio:id           DOID:2706  xsd:string  
1          0           graph  DOID:2704  rdfs:subClassOf  DOID:2706  _IRI        
1          0           graph  DOID:5485  rdfs:subClassOf  DOID:2706  _IRI