In release 1.7, a streaming version of sparqlSelectQuery() was added to the interface. This is to enable a complete dump of the contents of the triple-store.
This is difficult to implement, especially on instances that filter their results. Further, those filtered results do not fulfill the use case of dumping and restoring.
This method will be replaced by serializeAll() and serializeGraph() methods, which provide only the functionality required for the use case, and which ignore filters. This reduced contract should be much easier to satisfy.