+ * <p>
+ * Behavior to disable browser caching. This also means that the page
+ * automatically expires the first time after it is rendered.
+ * </p>
+ *
+ * <p>
+ * Important: To make sure that form data cannot be submitted twice for
+ * the same data using the back button, it is still necessary to explicitly call
+ * <code>getPage().getPageMap().remove(getPage());</code>
+ * in the <code>onSubmit</code> callback of the form.
+ * </p>