java.lang.NullPointerException: Attempt to invoke interface method 'java.lang.String java.lang.CharSequence.toString()' on a null object reference
	at de.bps.asist.module.canteen.CanteenSettingsFragment.onSharedPreferenceChanged(CanteenSettingsFragment.java:94)
	at android.app.SharedPreferencesImpl$EditorImpl.notifyListeners(SharedPreferencesImpl.java:497)
	at android.app.SharedPreferencesImpl$EditorImpl.apply(SharedPreferencesImpl.java:397)
	at android.preference.Preference.tryCommit(Preference.java:1418)
	at android.preference.Preference.persistString(Preference.java:1451)
	at android.preference.ListPreference.setValue(ListPreference.java:148)
	at android.preference.ListPreference.onDialogClosed(ListPreference.java:283)
	at android.preference.DialogPreference.onDismiss(DialogPreference.java:395)
	at android.app.Dialog$ListenersHandler.handleMessage(Dialog.java:1352)
	at android.os.Handler.dispatchMessage(Handler.java:102)
	at androidx.test.espresso.base.Interrogator.a(Interrogator.java:19)
	at androidx.test.espresso.base.UiControllerImpl.a(UiControllerImpl.java:166)
	at androidx.test.espresso.base.UiControllerImpl.a(UiControllerImpl.java:158)
	at androidx.test.espresso.base.UiControllerImpl.a(UiControllerImpl.java:138)
	at androidx.test.espresso.action.Tap$1.a(Tap.java:6)
	at androidx.test.espresso.action.GeneralClickAction.perform(GeneralClickAction.java:22)
	at androidx.test.espresso.ViewInteraction$SingleExecutionViewAction.perform(ViewInteraction.java:9)
	at androidx.test.espresso.ViewInteraction.a(ViewInteraction.java:79)
	at androidx.test.espresso.ViewInteraction.a(ViewInteraction.java:96)
	at androidx.test.espresso.ViewInteraction$1.call(ViewInteraction.java:3)
	at java.util.concurrent.FutureTask.run(FutureTask.java:237)
	at android.os.Handler.handleCallback(Handler.java:751)
	at android.os.Handler.dispatchMessage(Handler.java:95)
	at android.os.Looper.loop(Looper.java:154)
	at android.app.ActivityThread.main(ActivityThread.java:6121)
	at java.lang.reflect.Method.invoke(Native Method)
	at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:889)
	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:779)```