code: public static void loadClass(Context cx, Scriptable thisObj,
                                   Object[] args, Function funObj)
          throws IllegalAccessException, InstantiationException
      {
          Class<?> clazz = getClass(args);
          if (!Script.class.isAssignableFrom(clazz)) {
              throw reportRuntimeError("msg.must.implement.Script");
          }
          Script script = (Script) clazz.newInstance();
          script.exec(cx, thisObj);
      }
docs: Load and execute a script compiled to a class file.
  <p>
  This method is defined as a JavaScript function.
  When called as a JavaScript function, a single argument is
  expected. This argument should be the name of a class that
  implements the Script interface, as will any script
  compiled by jsc.
  
  @exception IllegalAccessException if access is not available
  to the class
  @exception InstantiationException if unable to instantiate
  the named class