convertVisitorIdToBin() public static method

This is used when building segments containing visitorId which could be an invalid string therefore throwing Unexpected PHP error [pack(): Type H: illegal hex digit i] severity [E_WARNING] It would be simply to silent fail the pack() call above but in all other cases, we don't expect an error, so better be safe and get the php error when something unexpected is happening
public static convertVisitorIdToBin ( string $id ) : string
$id string
return string binary string
 public function sendMessage($content, $fromAdmin = false, $idAutoMsg = false)
 {
     $hexVisitorId = Common::convertVisitorIdToBin($this->idvisitor);
     $sanitizeContent = Common::sanitizeInputValues($content);
     $additionnalParams = "";
     $microtime = microtime(true);
     $arguments = array($this->idsite, $hexVisitorId, $sanitizeContent, $microtime);
     if ($idAutoMsg) {
         $additionnalParams .= ", idautomsg = ?";
         $arguments[] = $idAutoMsg;
     }
     if ($fromAdmin) {
         $additionnalParams .= ", answerfrom = ?";
         $arguments[] = $fromAdmin;
     }
     $queryResult = Db::query("INSERT INTO " . Common::prefixTable('chat') . " SET idsite = ?, idvisitor = ?, content = ?, microtime = ?{$additionnalParams}", $arguments);
     if (!$fromAdmin) {
         ChatAcknowledgment::setLastSent($this->idsite, $this->idvisitor, $microtime);
         //ChatMail::sendNotificationToAdmin($this->idsite, $this->idvisitor, $sanitizeContent);
     }
     $insertedRow = Db::fetchRow("SELECT idmessage,microtime FROM " . Common::prefixTable('chat') . " WHERE idvisitor = ? AND microtime = ?", array($hexVisitorId, $microtime));
     return $insertedRow;
 }