}
/**
+ * Returns whether the image has already been inserted. An image is
+ * considered as having been inserted it its {@link #getKey() key} is not
+ * {@code null}.
+ *
+ * @return {@code true} if there is a key for this image, {@code false}
+ * otherwise
+ */
+ public boolean isInserted() {
+ return key != null;
+ }
+
+ /**
* Returns the creation time of this image.
*
* @return The creation time of this image (in milliseconds since 1970, Jan