+ * @param image
+ * The image to move down
+ * @return The image that the given image swapped the place with, or
+ * <code>null</code> if the image did not change its place
+ */
+ Image moveImageDown(Image image);
+
+ /**
+ * Returns the album image of this album, or {@code null} if no album image has
+ * been set.
+ *
+ * @return The image to show when this album is listed
+ */
+ Image getAlbumImage();
+
+ /**
+ * Returns whether this album contains any other albums or images.
+ *
+ * @return {@code true} if this album is empty, {@code false} otherwise
+ */
+ boolean isEmpty();
+
+ /**
+ * Returns whether this album is an identitiy’s root album.
+ *
+ * @return {@code true} if this album is an identity’s root album, {@code
+ * false} otherwise
+ */
+ boolean isRoot();
+
+ /**
+ * Returns the parent album of this album.
+ *
+ * @return The parent album of this album, or {@code null} if this album does
+ * not have a parent
+ */
+ Album getParent();
+
+ /**
+ * Sets the parent album of this album.
+ *
+ * @param parent
+ * The new parent album of this album