assertion  retraction  graph  subject             predicate        object               datatype    annotation
1          0           graph  obo:UBERON_0013522  rdfs:label       subdivision of tube  xsd:string  
1          0           graph  obo:UBERON_0013522  oio:id           UBERON:0013522       xsd:string  
1          0           graph  obo:UBERON_0013522  rdfs:subClassOf  obo:UBERON_0000064   _IRI        
1          0           graph  obo:UBERON_0013522  rdf:type         owl:Class            _IRI