question: private void updateSharedPreferencesEntry ( int notificationId , boolean remove ) { Set < String > notificationIds = new HashSet < String > ( mSharedPreferences . getStringSet ( WEBRTC_NOTIFICATION_IDS , new HashSet < String > ( ) ) ) ; if ( remove && ! notificationIds . isEmpty ( ) && notificationIds . contains ( String . valueOf ( notificationId ) ) ) { notificationIds . remove ( String . valueOf ( notificationId ) ) ; } else if ( ! remove ) { notificationIds . add ( String . valueOf ( notificationId ) ) ; } SharedPreferences . Editor sharedPreferenceEditor = mSharedPreferences . edit ( ) ; sharedPreferenceEditor . putStringSet ( WEBRTC_NOTIFICATION_IDS , notificationIds ) ; sharedPreferenceEditor . apply ( ) ; }
target:  Update shared preferences entry with ids of the visible notifications.