def setnx(*args)
      val = args.pop
      keys = args.flatten
      StorageFile.setnx(path, [*@parents, *keys], val)
    end
def setnx(*args)
      val = args.pop
      keys = args.flatten
      StorageFile.setnx(path, [*@parents, *keys], val)
    end
setnx(val)
 setnx(key, val)
 setnx(key1, key2, val)
 setnx([key], val)
 setnx([key1, key2], val)