code: public URL getUrl() throws MalformedURLException {
          if (this.url == null) {
              Handler handler = new Handler(this);
              String file = this.rootFile.getFile().toURI() + this.pathFromRoot + "!/";
              file = file.replace("file:////", "file://"); // Fix UNC paths
              this.url = new URL("jar", "", -1, file, handler);
          }
          return this.url;
      }
docs: Return a URL that can be used to access this JAR file. NOTE: the specified URL
  cannot be serialized and or cloned.
  
  @return the URL
  @throws MalformedURLException if the URL is malformed