assertion  retraction  graph  subject    predicate        object     datatype    annotation
1          0           graph  DOID:6848  rdfs:subClassOf  DOID:6788  _IRI        
1          0           graph  DOID:6788  oio:id           DOID:6788  xsd:string  
1          0           graph  DOID:6787  rdfs:subClassOf  DOID:6788  _IRI