RDFBuffer buffer = new RDFBuffer(adder);
// Note: any context information in the source document is discarded.
RDFSink pipe = new SingleContextPipe(buffer, valueFactory.createURI(graphUri), valueFactory);
RDFHandler handler = new SesameInputAdapter(useBlankNodes
? pipe
: new BNodeToURIFilter(pipe, valueFactory));
InputStream is;
try {