+typedef gboolean (*RetrieveAllCallback) (GObject *source,
+ guint num_msgs,
+ guint limit);
+
+/**
+ * CreateFolderUserCallback:
+ *
+ * @mail_op: the current #ModestMailOperation.
+ * @folder: a #TnyFolder summary item.
+ * @user_data: generic data passed to user defined function.
+ *
+ * This function will be called after get_msg_cb private function, which is
+ * used as tinymail operation callback. The private function fills private
+ * fields of mail operation and calls user defined callback if it exists.
+ */
+typedef void (*CreateFolderUserCallback) (ModestMailOperation *mail_op,
+ TnyFolderStore *parent_folder,
+ TnyFolder *new_folder,
+ gpointer user_data);
+