Component.java里的一段代码，不知道第二个方法上的注释是什么意思

/**     * Determines whether this component is enabled. An enabled component     * can respond to user input and generate events. Components are     * enabled initially by default. A component may be enabled or disabled by     * calling its <code>setEnabled</code> method.     * @return <code>true</code> if the component is enabled,     *          <code>false</code> otherwise     * @see #setEnabled     * @since JDK1.0     */    public boolean isEnabled() {        return isEnabledImpl();    }    /*     * This is called by the native code, so client code can't     * be called on the toolkit thread.     */    final boolean isEnabledImpl() {        return enabled;    }