protected function getSpecialCharacters() : array
    {
        if (self::$specialCharacters !== null) {
            return self::$specialCharacters;
        }

        return self::$specialCharacters = \array_keys(self::$specialCharactersMapping);
    }
protected function getSpecialCharacters() : array
    {
        if (self::$specialCharacters !== null) {
            return self::$specialCharacters;
        }

        return self::$specialCharacters = \array_keys(self::$specialCharactersMapping);
    }
protected function getSpecialCharacters ( ) : array { if ( self :: $ specialCharacters !== null ) { return self :: $ specialCharacters ; } return self :: $ specialCharacters = \ array_keys ( self :: $ specialCharactersMapping ) ; }
Returns the special characters for basic strings
Returns the special characters for basic strings