code: @Override
    public int chmod(String path, @mode_t long mode) {
      AlluxioURI uri = mPathResolverCache.getUnchecked(path);
  
      SetAttributePOptions options = SetAttributePOptions.newBuilder()
          .setMode(new alluxio.security.authorization.Mode((short) mode).toProto()).build();
      try {
        mFileSystem.setAttribute(uri, options);
      } catch (Throwable t) {
        LOG.error("Failed to change {} to mode {}", path, mode, t);
        return AlluxioFuseUtils.getErrorCode(t);
      }
  
      return 0;
    }
docs: Changes the mode of an Alluxio file.
  
  @param path the path of the file
  @param mode the mode to change to
  @return 0 on success, a negative value on error