assertion  retraction  graph  subject    predicate        object     datatype    annotation
1          0           graph  DOID:6407  rdfs:subClassOf  DOID:6214  _IRI        
1          0           graph  DOID:6405  rdfs:subClassOf  DOID:6214  _IRI        
1          0           graph  DOID:6214  oio:id           DOID:6214  xsd:string