assertion  retraction  graph  subject    predicate        object     datatype    annotation
1          0           graph  DOID:1974  rdfs:subClassOf  DOID:4236  _IRI        
1          0           graph  DOID:4236  oio:id           DOID:4236  xsd:string  
1          0           graph  DOID:4422  rdfs:subClassOf  DOID:4236  _IRI