assertion  retraction  graph  subject    predicate        object     datatype    annotation
1          0           graph  DOID:5751  rdfs:subClassOf  DOID:4073  _IRI        
1          0           graph  DOID:7234  rdfs:subClassOf  DOID:4073  _IRI        
1          0           graph  DOID:4073  oio:id           DOID:4073  xsd:string