code: public static function convert($input, $outputFormat = Code::FORMAT_ALNUM, $minLength = null)
      {
          if(is_int($minLength)) {
              $input += self::getMinForlength($outputFormat, $minLength);
          }
  
          static::throwUnlessAcceptable($outputFormat, $input);
  
          return self::convertBase($input, self::FORMAT_NUMBER, $outputFormat);
      }
docs: Get a code created from a number
  
  @param $input
  @param string $outputFormat One of Code::FORMAT_* constants. Default Code::FORMAT_ALNUM
  @param null $minLength
  
  @return string