java.lang.NullPointerException: Attempt to invoke interface method 'java.lang.Object[] java.util.Collection.toArray()' on a null object reference
	at java.util.ArrayList.addAll(ArrayList.java:588)
	at com.entitcs.office_attendance.activities.LeaveApprove$b.onPostExecute(Unknown Source:17)
	at android.os.AsyncTask.finish(AsyncTask.java:771)
	at android.os.AsyncTask.access$900(AsyncTask.java:199)
	at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:788)
	at android.os.Handler.dispatchMessage(Handler.java:106)
	at android.os.Looper.loop(Looper.java:233)
	at android.app.ActivityThread.main(ActivityThread.java:8030)
	at java.lang.reflect.Method.invoke(Native Method)
	at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:631)
	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:978)