assertion  retraction  graph  subject   predicate        object  datatype  annotation
1          0           graph  DOID:28   rdfs:subClassOf  DOID:7  _IRI      
1          0           graph  DOID:17   rdfs:subClassOf  DOID:7  _IRI      
1          0           graph  DOID:15   rdfs:subClassOf  DOID:7  _IRI      
1          0           graph  DOID:863  rdfs:subClassOf  DOID:7  _IRI      
1          0           graph  DOID:77   rdfs:subClassOf  DOID:7  _IRI