assertion  retraction  graph  subject    predicate        object     datatype    annotation
1          0           graph  DOID:6489  rdfs:subClassOf  DOID:3374  _IRI        
1          0           graph  DOID:3374  oio:id           DOID:3374  xsd:string  
1          0           graph  DOID:3373  rdfs:subClassOf  DOID:3374  _IRI