assertion  retraction  graph  subject    predicate        object     datatype    annotation
1          0           graph  DOID:7237  rdfs:subClassOf  DOID:7234  _IRI        
1          0           graph  DOID:7236  rdfs:subClassOf  DOID:7234  _IRI        
1          0           graph  DOID:7234  oio:id           DOID:7234  xsd:string