query and graph functions do not work for subgraphs

[schmid-bosch]

While this does not work:
res = kg.select('select * where {?s ?p ?o} limit 100', default_graph_uri='urn:test3') # , named_graph_uri='urn:test3') pprint.pprint(res)

... the following works:
res = kg.select('select * FROM <urn:test3> where {?s ?p ?o} limit 100') pprint.pprint(res)

From the documentation I understood that this should be equivalent.