code: @Nonnull
      public static String getDigestOf(@Nonnull File file) throws IOException {
          // Note: getDigestOf() closes the input stream.
          return getDigestOf(Files.newInputStream(fileToPath(file)));
      }
docs: Computes the MD5 digest of a file.
  @param file a file
  @return a 32-character string
  @throws IOException in case reading fails
  @since 1.525