assertion  retraction  graph  subject    predicate        object     datatype    annotation
1          0           graph  DOID:4006  oio:id           DOID:4006  xsd:string  
1          0           graph  DOID:6975  rdfs:subClassOf  DOID:4006  _IRI        
1          0           graph  DOID:6477  rdfs:subClassOf  DOID:4006  _IRI        
1          0           graph  DOID:6571  rdfs:subClassOf  DOID:4006  _IRI