assertion  retraction  graph  subject    predicate        object     datatype    annotation
1          0           graph  DOID:6017  oio:id           DOID:6017  xsd:string  
1          0           graph  DOID:6016  rdfs:subClassOf  DOID:6017  _IRI        
1          0           graph  DOID:6423  rdfs:subClassOf  DOID:6017  _IRI