throws Throwable
  public Value array_unshift(Env env,                             ArrayValue array,                             Value []values)    throws Throwable  {    if (array == null)      return NullValue.NULL;    for (int i = values.length - 1; i >= 0; i--) {      array.unshift(values[i]);    }    array.keyReset(0, NOT_STRICT);    return array;  }