private function setWillQoSLevelBit(int $QoSLevel): self
    {
        // Reset first the will QoS bits and proceed to set them
        $this->bitFlag &= ~8; // Third bit: 8
        $this->bitFlag &= ~16; // Fourth bit: 16

        if ($QoSLevel !== 0) {
            $this->logger->debug(sprintf(
                'Setting will QoS level %d flag (bit %d)',
                $QoSLevel,
                $QoSLevel * 8
            ));

            $this->bitFlag |= ($QoSLevel * 8);
        }

        return $this;
    }