assertion  retraction  graph  subject    predicate        object     datatype    annotation
1          0           graph  DOID:6947  oio:id           DOID:6947  xsd:string  
1          0           graph  DOID:7679  rdfs:subClassOf  DOID:6947  _IRI        
1          0           graph  DOID:7678  rdfs:subClassOf  DOID:6947  _IRI