public function __construct()
{
defined('UTF8_BOM') or define('UTF8_BOM', chr(0xef) . chr(0xbb) . chr(0xbf));
defined('UTF16_LITTLE_ENDIAN_BOM') or define('UTF16_LITTLE_ENDIAN_BOM', chr(0xff) . chr(0xfe));
defined('UTF16_BIG_ENDIAN_BOM') or define('UTF16_BIG_ENDIAN_BOM', chr(0xfe) . chr(0xff));
defined('UTF32_LITTLE_ENDIAN_BOM') or define('UTF32_LITTLE_ENDIAN_BOM', chr(0xff) . chr(0xfe) . chr(0x0) . chr(0x0));
defined('UTF32_BIG_ENDIAN_BOM') or define('UTF32_BIG_ENDIAN_BOM', chr(0x0) . chr(0x0) . chr(0xfe) . chr(0xff));
}