pocketmine\level\Level::requestChunk PHP Method

    public function requestChunk(int $x, int $z, Player $player)
    {
        $index = Level::chunkHash($x, $z);
        if (!isset($this->chunkSendQueue[$index])) {
            $this->chunkSendQueue[$index] = [];
        }
        $this->chunkSendQueue[$index][$player->getLoaderId()] = $player;
    }