assertion  retraction  graph  subject       predicate        object        datatype    annotation
1          0           graph  DOID:0050700  oio:id           DOID:0050700  xsd:string  
1          0           graph  DOID:0060036  rdfs:subClassOf  DOID:0050700  _IRI        
1          0           graph  DOID:3978     rdfs:subClassOf  DOID:0050700  _IRI