assertion  retraction  graph  subject    predicate        object    datatype    annotation
1          0           graph  DOID:4047  rdfs:subClassOf  DOID:270  _IRI        
1          0           graph  DOID:5296  rdfs:subClassOf  DOID:270  _IRI        
1          0           graph  DOID:270   oio:id           DOID:270  xsd:string  
1          0           graph  DOID:8022  rdfs:subClassOf  DOID:270  _IRI