code: public static void changeLocalFilePermission(String filePath, String perms) throws IOException {
      Files.setPosixFilePermissions(Paths.get(filePath), PosixFilePermissions.fromString(perms));
    }
docs: Changes local file's permission.
  
  @param filePath that will change permission
  @param perms the permission, e.g. "rwxr--r--"