pocketmine\Server::batchPackets PHP Method

    public function batchPackets(array $players, array $packets, $forceSync = false)
    {
        Timings::$playerNetworkTimer->startTiming();
        $str = "";
        foreach ($packets as $p) {
            if ($p instanceof DataPacket) {
                if (!$p->isEncoded) {
                    $p->encode();
                }
                $str .= Binary::writeUnsignedVarInt(strlen($p->buffer)) . $p->buffer;
            } else {
                $str .= Binary::writeUnsignedVarInt(strlen($p)) . $p;
            }
        }
        $targets = [];
        foreach ($players as $p) {
            if ($p->isConnected()) {
                $targets[] = $this->identifiers[spl_object_hash($p)];
            }
        }
        if (!$forceSync and $this->networkCompressionAsync) {
            $task = new CompressBatchedTask($str, $targets, $this->networkCompressionLevel);
            $this->getScheduler()->scheduleAsyncTask($task);
        } else {
            $this->broadcastPacketsCallback(zlib_encode($str, ZLIB_ENCODING_DEFLATE, $this->networkCompressionLevel), $targets);
        }
        Timings::$playerNetworkTimer->stopTiming();
    }

 public function putPacket(Player $player, DataPacket $packet, $needACK = false, $immediate = false)
 {
     if (isset($this->identifiers[$h = spl_object_hash($player)])) {
         $identifier = $this->identifiers[$h];
         $pk = null;
         if (!$packet->isEncoded) {
             $packet->encode();
         } elseif (!$needACK) {
             if (!isset($packet->__encapsulatedPacket)) {
                 $packet->__encapsulatedPacket = new CachedEncapsulatedPacket();
                 $packet->__encapsulatedPacket->identifierACK = null;
                 $packet->__encapsulatedPacket->buffer = chr(0xfe) . $packet->buffer;
                 $packet->__encapsulatedPacket->reliability = PacketReliability::RELIABLE_ORDERED;
                 $packet->__encapsulatedPacket->orderChannel = 0;
             }
             $pk = $packet->__encapsulatedPacket;
         }
         if (!$immediate and !$needACK and $packet::NETWORK_ID !== ProtocolInfo::BATCH_PACKET and Network::$BATCH_THRESHOLD >= 0 and strlen($packet->buffer) >= Network::$BATCH_THRESHOLD) {
             $this->server->batchPackets([$player], [$packet], true);
             return null;
         }
         if ($pk === null) {
             $pk = new EncapsulatedPacket();
             $pk->buffer = chr(0xfe) . $packet->buffer;
             $packet->reliability = PacketReliability::RELIABLE_ORDERED;
             $packet->orderChannel = 0;
             if ($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;
 }