assertion  retraction  graph  subject    predicate        object    datatype    annotation
1          0           graph  DOID:854   oio:id           DOID:854  xsd:string  
1          0           graph  DOID:853   rdfs:subClassOf  DOID:854  _IRI        
1          0           graph  DOID:3492  rdfs:subClassOf  DOID:854  _IRI