code: private void createMd5SumFile(FileSystem fs, String md5sum, Path remoteMd5Path) throws IOException {
      FSDataOutputStream os = null;
      try {
        os = fs.create(remoteMd5Path, true);
        os.writeBytes(md5sum);
        os.flush();
      } catch (Exception e) {
        LOG.error("{}", e);
      } finally {
        if (os != null) {
          os.close();
        }
      }
    }
docs: This method creates an file that contains a line with a MD5 sum
  
  @param fs
  FileSystem where to create the file.
  @param md5sum
  The string containing the MD5 sum.
  @param remoteMd5Path
  The path where to save the file.
  @throws IOException