java.lang.NullPointerException: Attempt to invoke virtual method 'void androidx.camera.lifecycle.ProcessCameraProvider.unbindAll()' on a null object reference
	at com.entitcs.office_attendance.FaceRecognitionRelated.helpers.MLVideoHelperActivity$3.onCheckedChanged(MLVideoHelperActivity.java:196)
	at android.widget.CompoundButton.setChecked(CompoundButton.java:180)
	at android.widget.ToggleButton.setChecked(ToggleButton.java:75)
	at android.widget.CompoundButton.onRestoreInstanceState(CompoundButton.java:606)
	at android.view.View.dispatchRestoreInstanceState(View.java:20065)
	at android.view.ViewGroup.dispatchRestoreInstanceState(ViewGroup.java:3908)
	at android.view.ViewGroup.dispatchRestoreInstanceState(ViewGroup.java:3908)
	at android.view.ViewGroup.dispatchRestoreInstanceState(ViewGroup.java:3908)
	at android.view.ViewGroup.dispatchRestoreInstanceState(ViewGroup.java:3908)
	at android.view.ViewGroup.dispatchRestoreInstanceState(ViewGroup.java:3908)
	at android.view.ViewGroup.dispatchRestoreInstanceState(ViewGroup.java:3908)
	at android.view.ViewGroup.dispatchRestoreInstanceState(ViewGroup.java:3908)
	at android.view.View.restoreHierarchyState(View.java:20043)
	at com.android.internal.policy.PhoneWindow.restoreHierarchyState(PhoneWindow.java:2166)
	at android.app.Activity.onRestoreInstanceState(Activity.java:1628)
	at android.app.Activity.performRestoreInstanceState(Activity.java:1576)
	at android.app.Instrumentation.callActivityOnRestoreInstanceState(Instrumentation.java:1354)
	at android.app.ActivityThread.handleStartActivity(ActivityThread.java:3547)
	at android.app.servertransaction.TransactionExecutor.performLifecycleSequence(TransactionExecutor.java:226)
	at android.app.servertransaction.TransactionExecutor.cycleToPath(TransactionExecutor.java:206)
	at android.app.servertransaction.TransactionExecutor.executeLifecycleState(TransactionExecutor.java:178)
	at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:102)
	at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2232)
	at android.os.Handler.dispatchMessage(Handler.java:107)
	at android.os.Looper.loop(Looper.java:238)
	at android.app.ActivityThread.main(ActivityThread.java:7824)
	at java.lang.reflect.Method.invoke(Native Method)
	at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492)
	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:981)