assertion  retraction  graph  subject    predicate        object     datatype    annotation
1          0           graph  DOID:7328  rdfs:subClassOf  DOID:6994  _IRI        
1          0           graph  DOID:6994  oio:id           DOID:6994  xsd:string  
1          0           graph  DOID:6993  rdfs:subClassOf  DOID:6994  _IRI