assertion  retraction  graph  subject    predicate        object    datatype    annotation
1          0           graph  DOID:709   rdfs:subClassOf  DOID:710  _IRI        
1          0           graph  DOID:710   oio:id           DOID:710  xsd:string  
1          0           graph  DOID:4334  rdfs:subClassOf  DOID:710  _IRI