assertion  retraction  graph  subject    predicate        object     datatype    annotation
1          0           graph  DOID:6170  rdfs:subClassOf  DOID:2151  _IRI        
1          0           graph  DOID:4217  rdfs:subClassOf  DOID:2151  _IRI        
1          0           graph  DOID:4001  rdfs:subClassOf  DOID:2151  _IRI        
1          0           graph  DOID:2151  oio:id           DOID:2151  xsd:string