- * is {@code null}, {@code null} is returned and the notification is
- * subsequently removed. Otherwise only posts that are posted by friend
- * Sones of the given Sone are retained; all other posts are removed.
+ * is {@code null} and {@code soneRequired} is {@code true}, {@code null} is
+ * returned and the notification is subsequently removed. Otherwise only
+ * posts that are posted by friend Sones of the given Sone are retained; all
+ * other posts are removed.