pocketmine\level\format\FullChunk::setZ PHP Method

    public function setZ($z);

 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 = \PHP_INT_SIZE === 8 ? ($chunkX & 0xffffffff) << 32 | $chunkZ & 0xffffffff : $chunkX . ":" . $chunkZ]) and $this->chunks[$index] !== $chunk) {
         $this->unloadChunk($chunkX, $chunkZ, \false);
     }
     $this->chunks[$index] = $chunk;
 }