assertion  retraction  graph  subject       predicate        object        datatype    annotation
1          0           graph  DOID:0050589  oio:id           DOID:0050589  xsd:string  
1          0           graph  DOID:8778     rdfs:subClassOf  DOID:0050589  _IRI        
1          0           graph  DOID:0060180  rdfs:subClassOf  DOID:0050589  _IRI