deparse fails with DoStmt

[herwinw]

irb(main):003:0> PgQuery.parse('DO $$ BEGIN PERFORM * FROM information_schema.tables; END $$ LANGUAGE plpgsql').deparse
RuntimeError: Can't deparse: DoStmt: {"args"=>[{"DefElem"=>{"defname"=>"as", "arg"=>{"String"=>{"str"=>" BEGIN PERFORM * FROM information_schema.tables; END "}}, "defaction"=>0, "location"=>3}}, {"DefElem"=>{"defname"=>"language", "arg"=>{"String"=>{"str"=>"plpgsql"}}, "defaction"=>0, "location"=>61}}]}

(I'll probably have a look at it next week, don't have time for it now, just creating this ticket as a reminder)