code: private void addJobJarToClassPath(String localJarFile, StringBuffer classPath) {
      File jobCacheDir = new File
        (new Path(localJarFile).getParent().toString());
      File[] libs = new File(jobCacheDir, "lib").listFiles();
      String sep = System.getProperty("path.separator");
  
      if (libs != null) {
        for (int i = 0; i < libs.length; i++) {
          classPath.append(sep); // add libs from jar to classpath
          classPath.append(libs[i]);
        }
      }
      classPath.append(sep);
      classPath.append(new File(jobCacheDir, "classes"));
      classPath.append(sep);
      classPath.append(jobCacheDir);
    }
docs: Given the path to the localized job jar file, add it's constituents to
  the classpath