assertion  retraction  graph  subject     predicate        object     datatype    annotation
1          0           graph  DOID:7708   rdfs:subClassOf  DOID:4284  _IRI        
1          0           graph  DOID:12239  rdfs:subClassOf  DOID:4284  _IRI        
1          0           graph  DOID:4284   oio:id           DOID:4284  xsd:string