public function toBinary()
{
$binary = hex2bin(str_pad(dechex(MBString::ord($this->signature)), 2, 0, STR_PAD_LEFT));
$binary .= hex2bin(str_pad(dechex(count($this->tsProperty)), 2, 0, STR_PAD_LEFT));
foreach ($this->tsProperty as $tsProperty) {
$binary .= $tsProperty->toBinary();
}
return $binary;
}