assertion  retraction  graph  subject    predicate        object     datatype    annotation
1          0           graph  DOID:6838  rdfs:subClassOf  DOID:4895  _IRI        
1          0           graph  DOID:6837  rdfs:subClassOf  DOID:4895  _IRI        
1          0           graph  DOID:4895  oio:id           DOID:4895  xsd:string