assertion  retraction  graph  subject    predicate        object     datatype    annotation
1          0           graph  DOID:4839  rdfs:subClassOf  DOID:4840  _IRI        
1          0           graph  DOID:4840  oio:id           DOID:4840  xsd:string  
1          0           graph  DOID:4286  rdfs:subClassOf  DOID:4840  _IRI