public ClientChunk CreateClientChunk(ChunkOctree<ClientChunk> octree, long x, long y, long z)
        {
            var existing = octree.Get(x, y, z);

            if (existing != null)
            {
                return existing;
            }

            var @new = new ClientChunk(x, y, z);
            octree.Set(@new);

            return @new;
        }