pocketmine\network\protocol\DataPacket::pid PHP Method

    public function pid()
    {
        return $this::NETWORK_ID;
    }

 public function putPacket(Player $player, DataPacket $packet, $needACK = \false, $immediate = \false)
 {
     if (isset($this->identifiers[$player])) {
         $identifier = $this->identifiers[$player];
         $pk = \null;
         if (!$packet->isEncoded) {
             $packet->encode();
         } elseif (!$needACK) {
             if (!isset($packet->__encapsulatedPacket)) {
                 $packet->__encapsulatedPacket = new CachedEncapsulatedPacket();
                 $packet->__encapsulatedPacket->identifierACK = \null;
                 $packet->__encapsulatedPacket->buffer = $packet->buffer;
                 if ($packet->getChannel() !== 0) {
                     $packet->__encapsulatedPacket->reliability = 3;
                     $packet->__encapsulatedPacket->orderChannel = $packet->getChannel();
                     $packet->__encapsulatedPacket->orderIndex = 0;
                 } else {
                     $packet->__encapsulatedPacket->reliability = 2;
                 }
             }
             $pk = $packet->__encapsulatedPacket;
         }
         if (!$immediate and !$needACK and $packet->pid() !== ProtocolInfo::BATCH_PACKET and Network::$BATCH_THRESHOLD >= 0 and \strlen($packet->buffer) >= Network::$BATCH_THRESHOLD) {
             $this->server->batchPackets([$player], [$packet], \true, $packet->getChannel());
             return \null;
         }
         if ($pk === \null) {
             $pk = new EncapsulatedPacket();
             $pk->buffer = $packet->buffer;
             if ($packet->getChannel() !== 0) {
                 $packet->reliability = 3;
                 $packet->orderChannel = $packet->getChannel();
                 $packet->orderIndex = 0;
             } else {
                 $packet->reliability = 2;
             }
             if ($needACK === \true) {
                 $pk->identifierACK = $this->identifiersACK[$identifier]++;
             }
         }
         $this->interface->sendEncapsulated($identifier, $pk, ($needACK === \true ? RakLib::FLAG_NEED_ACK : 0) | ($immediate === \true ? RakLib::PRIORITY_IMMEDIATE : RakLib::PRIORITY_NORMAL));
         return $pk->identifierACK;
     }
     return \null;
 }