pocketmine\Server::broadcastPacketsCallback PHP Method

    public function broadcastPacketsCallback($data, array $identifiers)
    {
        $pk = new BatchPacket();
        $pk->payload = $data;
        $pk->encode();
        $pk->isEncoded = true;
        foreach ($identifiers as $i) {
            if (isset($this->players[$i])) {
                $this->players[$i]->dataPacket($pk);
            }
        }
    }

 public function onCompletion(Server $server)
 {
     $server->broadcastPacketsCallback($this->final, unserialize($this->targets));
     $this->level = null;
     $this->data = null;
     $this->final = null;
     $this->targets = null;
     unset($this->level);
     unset($this->data);
     unset($this->final);
     unset($this->targets);
 }