assertion  retraction  graph  subject    predicate        object     datatype    annotation
1          0           graph  DOID:6518  rdfs:subClassOf  DOID:2068  _IRI        
1          0           graph  DOID:2068  oio:id           DOID:2068  xsd:string  
1          0           graph  DOID:5382  rdfs:subClassOf  DOID:2068  _IRI