code: public static function forString($string, $code = self::CODE_FOR_STRING, Exception $previous = null)
      {
          $message = self::DEFAULT_MESSAGE . sprintf(self::MESSAGE_EXTENSION_FOR_STRING_FORMAT, $string);
  
          return new static($message, $code, $previous);
      }
docs: Creates an exception instance for a given string.
  
  @param string $string The string that failed to convert the encoding of.
  @param int $code The exception code.
  @param Exception|null $previous A previous exception used for chaining.
  @return static