docs: public final void initApplicationClassLoader(ClassLoader loader)
      {
          if (loader == null)
              throw new IllegalArgumentException("loader is null");
          if (!Kit.testIfCanLoadRhinoClasses(loader))
              throw new IllegalArgumentException(
                  "Loader can not resolve Rhino classes");
  
          if (this.applicationClassLoader != null)
              throw new IllegalStateException(
                  "applicationClassLoader can only be set once");
          checkNotSealed();
  
          this.applicationClassLoader = loader;
      }