docs: static String readFileFromJarfile(String fulljarpath) throws IOException {
          assert (fulljarpath.contains(".jar!"));
  
          String[] paths = fulljarpath.split("!");
          if (paths[0].startsWith("file:"))
              paths[0] = paths[0].substring("file:".length());
          paths[1] = paths[1].substring(1);
  
          return readFileFromJarfile(paths[0], paths[1]);
      }