pocketmine\level\format\leveldb\LevelDB::setChunk PHP Method

    public function setChunk($chunkX, $chunkZ, FullChunk $chunk)
    {
        if (!$chunk instanceof Chunk) {
            throw new ChunkException("Invalid Chunk class");
        }
        $chunk->setProvider($this);
        $chunk->setX($chunkX);
        $chunk->setZ($chunkZ);
        if (isset($this->chunks[$index = Level::chunkHash($chunkX, $chunkZ)]) and $this->chunks[$index] !== $chunk) {
            $this->unloadChunk($chunkX, $chunkZ, false);
        }
        $this->chunks[$index] = $chunk;
    }