assertion  retraction  graph  subject    predicate        object    datatype    annotation
1          0           graph  DOID:8272  rdfs:subClassOf  DOID:738  _IRI        
1          0           graph  DOID:738   oio:id           DOID:738  xsd:string  
1          0           graph  DOID:7488  rdfs:subClassOf  DOID:738  _IRI