code: protected void loadFSImage(ImageInputStream iis, File imageFile) throws IOException {
      MD5Hash expectedMD5 = MD5FileUtils.readStoredMd5ForFile(imageFile);
      if (expectedMD5 == null) {
        throw new IOException("No MD5 file found corresponding to image file "
            + imageFile);
      }
      iis.setImageDigest(expectedMD5);
      loadFSImage(iis);
    }
docs: Load the image namespace from the given image file, verifying it against
  the MD5 sum stored in its associated .md5 file.