assertion  retraction  graph  subject    predicate        object    datatype    annotation
1          0           graph  DOID:535   rdfs:subClassOf  DOID:150  _IRI        
1          0           graph  DOID:1561  rdfs:subClassOf  DOID:150  _IRI        
1          0           graph  DOID:150   oio:id           DOID:150  xsd:string