code: public FileStatus getFileStatus(final Path f, final boolean useStandby)
      throws IOException {
      return new StandbyCaller<FileStatus>() {
        @Override
        FileStatus call(DistributedFileSystem fs) throws IOException {
          return fs.getFileStatus(f);
        }
      }.callFS(useStandby);
    }
docs: Return the stat information about a file.
  @param f path
  @param useStandby flag indicating whether to read from standby avatar
  @throws FileNotFoundException if the file does not exist.