assertion  retraction  graph  subject       predicate        object        datatype    annotation
1          0           graph  DOID:0080903  oio:id           DOID:0080903  xsd:string  
1          0           graph  DOID:7841     rdfs:subClassOf  DOID:0080903  _IRI        
1          0           graph  DOID:7631     rdfs:subClassOf  DOID:0080903  _IRI