let sm = Lrc::new(SourceMap::new(FilePathMapping::empty()));
let emitter = EmitterWriter::new(box io::sink(), None, false, false, false, None, false);
let handler = Handler::with_emitter(false, None, box emitter);
let sess = ParseSess::with_span_handler(handler, sm);
let sm = Lrc::new(SourceMap::new(FilePathMapping::empty()));
let emitter = EmitterWriter::new(box io::sink(), None, false, false, false, None, false);
let handler = Handler::with_emitter(false, None, box emitter);
let sess = ParseSess::with_span_handler(handler, sm);