assertion  retraction  graph  subject       predicate        object        datatype    annotation
1          0           graph  DOID:0050739  oio:id           DOID:0050739  xsd:string  
1          0           graph  DOID:0050737  rdfs:subClassOf  DOID:0050739  _IRI        
1          0           graph  DOID:0050736  rdfs:subClassOf  DOID:0050739  _IRI