assertion  retraction  graph  subject     predicate        object     datatype    annotation
1          0           graph  DOID:4876   oio:id           DOID:4876  xsd:string  
1          0           graph  DOID:4875   rdfs:subClassOf  DOID:4876  _IRI        
1          0           graph  DOID:12003  rdfs:subClassOf  DOID:4876  _IRI