GAsyncInitiable object. This is
similar to gObjectNew but also initializes the object asyncronously.gAsyncInitableNewAsync(object.type, io.priority, cancellable,  callback, user.data, ...)object.typeGType supporting GAsyncInitable.io.prioritycancellableGCancellable object, NULL to ignore.callbackGAsyncReadyCallback to call when the initialization is
finisheduser.data...NULL.callback will be called. You can
then call gAsyncInitableNewFinish to get new object and check for
any errors.
  Since 2.22