code: protected function peek($nb = 1)
      {
          $i = 0;
          $tokens = $this->tokens;
          while ($token = array_shift($tokens)) {
              if (is_array($token) && in_array($token[0], array(T_WHITESPACE, T_COMMENT, T_DOC_COMMENT))) {
                  continue;
              }
  
              ++$i;
              if ($i == $nb) {
                  return $token;
              }
          }
      }
docs: Peeks the next token.
  
  @param int $nb
  
  @return string|null