assertion  retraction  graph  subject   predicate            object              datatype    annotation
1          0           graph  DOID:505  rdfs:label           hobnail hemangioma  xsd:string  
1          0           graph  DOID:505  oio:id               DOID:505            xsd:string  
1          0           graph  DOID:505  oio:hasOBONamespace  disease_ontology    xsd:string  
1          0           graph  DOID:505  rdfs:subClassOf      DOID:255            _IRI        
1          0           graph  DOID:505  rdf:type             owl:Class           _IRI