assertion  retraction  graph  subject    predicate        object     datatype    annotation
1          0           graph  DOID:3192  rdfs:subClassOf  DOID:2001  _IRI        
1          0           graph  DOID:2001  oio:id           DOID:2001  xsd:string  
1          0           graph  DOID:5155  rdfs:subClassOf  DOID:2001  _IRI