assertion  retraction  graph  subject    predicate        object     datatype    annotation
1          0           graph  DOID:4549  oio:id           DOID:4549  xsd:string  
1          0           graph  DOID:7903  rdfs:subClassOf  DOID:4549  _IRI        
1          0           graph  DOID:4548  rdfs:subClassOf  DOID:4549  _IRI        
1          0           graph  DOID:7902  rdfs:subClassOf  DOID:4549  _IRI