@Test
public void testLexer() {

  Parser<List<Token>> parser = Terminals.LongLiteral.DEC_TOKENIZER.lexer(Scanners.WHITESPACES);
  assertEquals(Arrays.<Token>asList(), parser.parse("", mode));
  assertEquals(Arrays.<Token>asList(), parser.parse("  ", mode));
  assertEquals(Arrays.<Token>asList(new Token(1, 2, 12L)), parser.parse(" 12  ", mode));
  assertEquals(Arrays.<Token>asList(new Token(0, 2, 12L), new Token(3, 1, 3L)),
      parser.parse("12 3  ", mode));
}