assertion  retraction  graph  subject    predicate        object     datatype    annotation
1          0           graph  DOID:6354  oio:id           DOID:6354  xsd:string  
1          0           graph  DOID:8144  rdfs:subClassOf  DOID:6354  _IRI        
1          0           graph  DOID:7230  rdfs:subClassOf  DOID:6354  _IRI