qparse --print=quad \
'SELECT * { {?s ?p ?o } UNION { GRAPH ?g { ?a ?b ?c }}}'
==>
(union
(quadpattern (quad <urn:x-arq:DefaultGraphNode> ?s ?p ?o))
(quadpattern (quad ?g ?a ?b ?c)))
qparse --print=op \
'SELECT * { {?s ?p ?o } UNION { GRAPH ?g { ?a ?b ?c }}}'
==>
(union
(bgp (triple ?s ?p ?o))
(graph ?g
(bgp (triple ?a ?b ?c))))
