assertion  retraction  graph  subject    predicate        object     datatype    annotation
1          0           graph  DOID:3907  oio:id           DOID:3907  xsd:string  
1          0           graph  DOID:6510  rdfs:subClassOf  DOID:3907  _IRI        
1          0           graph  DOID:7045  rdfs:subClassOf  DOID:3907  _IRI