code: private static void completeManifest(Manifest manifest, URL url) {
  
      String path = url.getPath();
      int start = 0;
      int end = path.length();
      if (path.endsWith(JAR_SUFFIX)) {
        // 4 for ".jar"
        end = end - JAR_SUFFIX.length() + 4;
        start = path.lastIndexOf('/', end) + 1;
      }
      String source = path.substring(start, end);
      manifest.getMainAttributes().put(MANIFEST_SOURCE, source);
    }
docs: This method adds dynamic attributes to the given {@code manifest}.
  
  @param manifest is the {@link Manifest} to modify.
  @param url is the {@link URL} with the source of the manifest.