assertion  retraction  graph  subject    predicate        object     datatype    annotation
1          0           graph  DOID:4955  oio:id           DOID:4955  xsd:string  
1          0           graph  DOID:6379  rdfs:subClassOf  DOID:4955  _IRI        
1          0           graph  DOID:8243  rdfs:subClassOf  DOID:4955  _IRI