protected function compress(string $row, ?string $lastRow): string
    {
        if ($row === $lastRow) {
            return ':';
        }

        $row = $this->compressTrailingZerosOrOnes($row);
        $row = $this->compressRepeatingCharacters($row);

        return $row;
    }
protected function compress(string $row, ?string $lastRow): string
    {
        if ($row === $lastRow) {
            return ':';
        }

        $row = $this->compressTrailingZerosOrOnes($row);
        $row = $this->compressRepeatingCharacters($row);

        return $row;
    }
protected function compress ( string $ row , ? string $ lastRow ) : string { if ( $ row === $ lastRow ) { return ':' ; } $ row = $ this -> compressTrailingZerosOrOnes ( $ row ) ; $ row = $ this -> compressRepeatingCharacters ( $ row ) ; return $ row ; }
Compress a row of ASCII hexadecimal data.

@param string $row
@param string $lastRow
@return string
Compress a row of ASCII hexadecimal data .