original_string: public static function encode($data, $pad = null) {
  		$str = str_replace(array('+', '/'), array('-', '_'), base64_encode($data));
  		if (!$pad) {
  			$str = rtrim($str, '=');
  		}
  		return $str;
  	}
code: public static function encode($data, $pad = null) {
  		$str = str_replace(array('+', '/'), array('-', '_'), base64_encode($data));
  		if (!$pad) {
  			$str = rtrim($str, '=');
  		}
  		return $str;
  	}
code_tokens: public static function encode ( $ data , $ pad = null ) { $ str = str_replace ( array ( '+' , '/' ) , array ( '-' , '_' ) , base64_encode ( $ data ) ) ; if ( ! $ pad ) { $ str = rtrim ( $ str , '=' ) ; } return $ str ; }
docstring: encode a string
  
  @param string $data
  @param string $pad
  @return string
docstring_tokens: encode a string