assertion  retraction  graph  subject    predicate        object     datatype    annotation
1          0           graph  DOID:3419  rdfs:subClassOf  DOID:1891  _IRI        
1          0           graph  DOID:8869  rdfs:subClassOf  DOID:1891  _IRI        
1          0           graph  DOID:1891  oio:id           DOID:1891  xsd:string