assertion  retraction  graph  subject    predicate            object            datatype    annotation
1          0           graph  DOID:3281  rdfs:label           combined thymoma  xsd:string  
1          0           graph  DOID:3281  oio:id               DOID:3281         xsd:string  
1          0           graph  DOID:3281  oio:hasOBONamespace  disease_ontology  xsd:string  
1          0           graph  DOID:3281  rdfs:subClassOf      DOID:3275         _IRI        
1          0           graph  DOID:3281  rdf:type             owl:Class         _IRI