Does it work with nested graphs?

[renyuneyun]

I'm exploring this software on a local endpoint. I modified the services.js on the dbpedia branch and it works.
The question I have is: it works with a single graph. But when it contains nested graphs, I'm having no idea how to make it work.
I see the SPARQL queries generated are in this form:

SELECT DISTINCT ?var9 ?var8 ?prop8 WHERE {
  ?var8 ?prop8 ?var9 .
  FILTER isIRI(?var9)
}

But for a nested graph, it needs to be:

SELECT DISTINCT ?var9 ?var8 ?prop8 WHERE {
  GRAPH ?g {
    ?var8 ?prop8 ?var9 .
    FILTER isIRI(?var9)
  }
}