assertion  retraction  graph  subject       predicate        object     datatype    annotation
1          0           graph  DOID:0050927  rdfs:subClassOf  DOID:1737  _IRI        
1          0           graph  DOID:1737     oio:id           DOID:1737  xsd:string  
1          0           graph  DOID:10022    rdfs:subClassOf  DOID:1737  _IRI