code: public static function parseFromCamelCaseExtended(
          $identifier,
          $upper = '\xc0-\xd6\xd8-\xdf',
          $lower = '\x7f-\xbf\xd7\xe0-\xff'
      ) {
  
          $camelCasePattern = '/' .
              // Do not attempt to split along a capital letter at the
              // beginning of the string:
              '(?!^)' .
              // Split along any of the following:
              '(' .
                  // A sequence that starts with a capital letter following a
                  // lowercase letter or number:
                  '(?<=[a-z0-9' . $lower . '])(?=[A-Z' . $upper . '])' .
                  // Or
                  '|' .
                  // A sequence that starts with a capital letter followed by a
                  // lowercase letter or number:
                  '(?=[A-Z' . $upper . '][a-z' . $lower . '])' .
              ')' .
          // Accept multibyte characters in the identifier
          '/u';
  
          return preg_split($camelCasePattern, $identifier);
      }
docs: Inherit Doc from Interfaces\Parser