android-support-v4.jar 混淆出錯

將工程混淆下，但是發現有如下的錯誤：

 [java] Warning: android.support.v4.view.accessibility.AccessibilityNodeProviderCompatJellyBean$1: can't find superclass or interface android.view.accessibility.AccessibilityNodeProvider
     [java] Warning: android.support.v4.app.NavUtilsJB: can't find referenced method 'android.content.Intent getParentActivityIntent()' in class android.app.Activity
     [java] Warning: android.support.v4.app.NavUtilsJB: can't find referenced method 'boolean shouldUpRecreateTask(android.content.Intent)' in class android.app.Activity
     [java] Warning: android.support.v4.app.NavUtilsJB: can't find referenced method 'boolean navigateUpTo(android.content.Intent)' in class android.app.Activity
     [java] Warning: android.support.v4.app.NavUtilsJB: can't find referenced field 'java.lang.String parentActivityName' in class android.content.pm.ActivityInfo
     [java] Warning: android.support.v4.app.NotificationCompatJellybean: can't find referenced method 'android.app.Notification$Builder setSubText(java.lang.CharSequence)' in class android.app.Notification$Builder
     [java] Warning: android.support.v4.app.NotificationCompatJellybean: can't find referenced method 'android.app.Notification$Builder setUsesChronometer(boolean)' in class android.app.Notification$Builder
     [java] Warning: android.support.v4.app.NotificationCompatJellybean: can't find referenced method 'android.app.Notification$Builder setPriority(int)' in class android.app.Notification$Builder
     [java] Warning: android.support.v4.app.NotificationCompatJellybean: can't find referenced method 'android.app.Notification$Builder addAction(int,java.lang.CharSequence,android.app.PendingIntent)' in class android.app.Notification$Builder

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由於之前混淆這個 android-support-v4.jar包是沒有問題的，

可想問題出現：目前的這個android-support-v4.jar JAR包上，果然，當初建工程的時候，引導工程默認是

使用最新的API-17來建工程的，所以系統默認使用支持4.1 Jelly Bean 的android-support-v4.jar JAR包,

打包的時候 API-level調到 >= 16即可,或者將 /libs/android-support-v4.jar 替換成較老版本的。