public function acceptWhiteSpace( $additional = '' )
    {
        $this->buffer = ltrim( $this->buffer, self::WHITE_SPACE . $additional );

        while ( substr( $this->buffer, 0, 2 ) == '/*' )
        {
            $this->buffer = ltrim(
                preg_replace( '#/\*.*?\*/s#', '', $this->buffer ),
                self::WHITE_SPACE . $additional
            );
        }
    }