assertion  retraction  graph  subject    predicate        object     datatype    annotation
1          0           graph  DOID:1642  rdfs:subClassOf  DOID:3004  _IRI        
1          0           graph  DOID:3004  oio:id           DOID:3004  xsd:string  
1          0           graph  DOID:7521  rdfs:subClassOf  DOID:3004  _IRI