initial (untested) addition of ReadOnlyGraphAggregate - needed to support SPARQL's SELECT ... FROM NAMED < .. graphID ..> FROM NAMED < .. graph2ID ..> WHERE { .. }
initial (untested) addition of ReadOnlyGraphAggregate - needed to support SPARQL's SELECT ... FROM NAMED < .. graphID ..> FROM NAMED < .. graph2ID ..> WHERE { .. }

git-svn-id: 60eb48102d1ca0c284ab3654bef916b01e1b221b@796 4f84a9ca-5c3e-0410-8a68-0bdf370325d5

nwebs/rdflib