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$3.onCheckedChanged(MLVideoHelperActivity.java:215)
	at android.widget.CompoundButton.setChecked(CompoundButton.java:171)
	at android.widget.ToggleButton.setChecked(ToggleButton.java:71)
	at android.widget.CompoundButton.onRestoreInstanceState(CompoundButton.java:566)
	at android.view.View.dispatchRestoreInstanceState(View.java:18699)
	at android.view.ViewGroup.dispatchRestoreInstanceState(ViewGroup.java:3889)
	at android.view.ViewGroup.dispatchRestoreInstanceState(ViewGroup.java:3889)
	at android.view.ViewGroup.dispatchRestoreInstanceState(ViewGroup.java:3889)
	at android.view.ViewGroup.dispatchRestoreInstanceState(ViewGroup.java:3889)
	at android.view.ViewGroup.dispatchRestoreInstanceState(ViewGroup.java:3889)
	at android.view.ViewGroup.dispatchRestoreInstanceState(ViewGroup.java:3889)
	at android.view.ViewGroup.dispatchRestoreInstanceState(ViewGroup.java:3889)
	at android.view.View.restoreHierarchyState(View.java:18677)
	at com.android.internal.policy.PhoneWindow.restoreHierarchyState(PhoneWindow.java:2135)
	at android.app.Activity.onRestoreInstanceState(Activity.java:1173)
	at android.app.Activity.performRestoreInstanceState(Activity.java:1128)
	at android.app.Instrumentation.callActivityOnRestoreInstanceState(Instrumentation.java:1318)
	at android.app.ActivityThread.handleStartActivity(ActivityThread.java:3016)
	at android.app.servertransaction.TransactionExecutor.performLifecycleSequence(TransactionExecutor.java:185)
	at android.app.servertransaction.TransactionExecutor.cycleToPath(TransactionExecutor.java:170)
	at android.app.servertransaction.TransactionExecutor.executeLifecycleState(TransactionExecutor.java:147)
	at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:73)
	at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1858)
	at android.os.Handler.dispatchMessage(Handler.java:106)
	at android.os.Looper.loop(Looper.java:201)
	at android.app.ActivityThread.main(ActivityThread.java:6820)
	at java.lang.reflect.Method.invoke(Native Method)
	at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:547)
	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:922)