 by using GroupForm
  = sep [ text "then group", nest 2 (pprBy by), nest 2 (ptext (sLit "using") <+> ppr using)]

pprBy :: O
pprTransStmt by using GroupForm
  = sep [ text "then group", nest 2 (pprBy by), nest 2 (ptext (sLit "using") <+> ppr using)]
pprTransStmt by using GroupForm
  = sep [ text "then group", nest 2 (pprBy by), nest 2 (ptext (sLit "using") <+> ppr using)]