static Object js_createAdpter(Context cx, Scriptable scope, Object[] args) {
    int N = args.length;
    if (N == 0) {
      throw ScriptRuntime.typeError0("msg.adapter.zero.args");
    }

    Class superClass = null;
    Class[] intfs = new Class[N - 1];
    int interfaceCount = 0;
    for (int i = 0; i != N - 1; ++i) {
      Object arg = args[i];
      if (!(arg instanceof NativeJavaClass)) {
        throw ScriptRuntime.typeError2(
            "msg.not.java.class.arg", String.valueOf(i), ScriptRuntime.toString(arg));
      }
      Class c = ((NativeJavaClass) arg).getClassObject();
      if (!c.isInterface()) {
        if (superClass != null) {
          throw ScriptRuntime.typeError2("msg.only.one.super", superClass.getName(), c.getName());
        }
        superClass = c;
      } else {
        intfs[interfaceCount++] = c;
      }
    }

    if (superClass == null) superClass = ScriptRuntime.ObjectClass;

    Class[] interfaces = new Class[interfaceCount];
    System.arraycopy(intfs, 0, interfaces, 0, interfaceCount);
    Scriptable obj = ScriptRuntime.toObject(cx, scope, args[N - 1]);

    Class adapterClass = getAdapterClass(scope, superClass, interfaces, obj);

    Class[] ctorParms = {ScriptRuntime.ContextFactoryClass, ScriptRuntime.ScriptableClass};
    Object[] ctorArgs = {cx.getFactory(), obj};
    try {
      Object adapter = adapterClass.getConstructor(ctorParms).newInstance(ctorArgs);
      return getAdapterSelf(adapterClass, adapter);
    } catch (Exception ex) {
      throw Context.throwAsScriptRuntimeEx(ex);
    }
  }
  public static Function getFunction(Scriptable obj, String functionName) {
    Object x = ScriptableObject.getProperty(obj, functionName);
    if (x == Scriptable.NOT_FOUND) {
      // This method used to swallow the exception from calling
      // an undefined method. People have come to depend on this
      // somewhat dubious behavior. It allows people to avoid
      // implementing listener methods that they don't care about,
      // for instance.
      return null;
    }
    if (!(x instanceof Function)) throw ScriptRuntime.notFunctionError(x, functionName);

    return (Function) x;
  }
 private static ObjToIntMap getObjectFunctionNames(Scriptable obj) {
   Object[] ids = ScriptableObject.getPropertyIds(obj);
   ObjToIntMap map = new ObjToIntMap(ids.length);
   for (int i = 0; i != ids.length; ++i) {
     if (!(ids[i] instanceof String)) continue;
     String id = (String) ids[i];
     Object value = ScriptableObject.getProperty(obj, id);
     if (value instanceof Function) {
       Function f = (Function) value;
       int length = ScriptRuntime.toInt32(ScriptableObject.getProperty(f, "length"));
       if (length < 0) {
         length = 0;
       }
       map.put(id, length);
     }
   }
   return map;
 }