Helper function for constructing GAsyncInitable object. This is similar to g_object_new_valist() but also initializes the object asynchronously.
When the initialization is finished, callback will be called. You can then call g_async_initable_new_finish() to get the new object and check for any errors.
the name of the first property, followed by the value, and other property value pairs, and ended by NULL.
The var args list generated from first_property_name.
the [I/O priority][io-priority] of the operation
optional gio.Cancellable object, NULL to ignore.
a GAsyncReadyCallback to call when the initialization is finished
the data to pass to callback function