Add a little bit of documentation on summary vs. stacked notifications

k9mail/src/main/java/com/fsck/k9/notification/NewMailNotifications.java

@@ -12,6 +12,16 @@ import com.fsck.k9.activity.MessageReference;
 import com.fsck.k9.mailstore.LocalMessage;
 
 
+/**
+ * Handle notifications for new messages.
+ * <p>
+ * We call the notification shown on the device <em>summary notification</em>, even when there's only one new message.
+ * Notifications on an Android Wear device are displayed as a stack of cards and that's why we call them <em>stacked
+ * notifications</em>. We have to keep track of stacked notifications individually and recreate/update the summary
+ * notification when one or more of the stacked notifications are added/removed.<br>
+ * {@link NotificationData} keeps track of all data required to (re)create the actual system notifications.
+ * </p>
+ */
 class NewMailNotifications {
     private final NotificationController controller;
     private final NotificationContentCreator contentCreator;

k9mail/src/main/java/com/fsck/k9/notification/WearNotifications.java

@@ -131,7 +131,6 @@ class WearNotifications extends BaseNotifications {
         int icon = R.drawable.ic_action_mark_as_read_dark;
         String title = context.getString(R.string.notification_action_mark_as_read);
 
-
         MessageReference messageReference = holder.content.messageReference;
         int notificationId = holder.notificationId;
         PendingIntent action = actionCreator.createMarkMessageAsReadPendingIntent(messageReference, notificationId);