throws Throwable
  public boolean session_register(Env env, Value []values)    throws Throwable  {    Value session = env.getGlobalValue("_SESSION");    if (! session.isArray()) {      session_start(env);      session = env.getGlobalValue("_SESSION");    }    for (int i = 0; i < values.length; i++)      sessionRegisterImpl(env, (ArrayValue) session, values[i]);    return true;  }