assertion  retraction  graph  subject    predicate        object     datatype    annotation
1          0           graph  DOID:6381  rdfs:subClassOf  DOID:4708  _IRI        
1          0           graph  DOID:4708  oio:id           DOID:4708  xsd:string  
1          0           graph  DOID:6553  rdfs:subClassOf  DOID:4708  _IRI