original_string: public static function encode($string)
      {
          return is_null($string) ? self::NULL : strtr($string, self::$encodeMap);
      }
code: public static function encode($string)
      {
          return is_null($string) ? self::NULL : strtr($string, self::$encodeMap);
      }
code_tokens: public static function encode ( $ string ) { return is_null ( $ string ) ? self :: NULL : strtr ( $ string , self :: $ encodeMap ) ; }
docstring: Encode string for sending to server
  
  @param $string
  @return string
docstring_tokens: Encode string for sending to server