Function g_async_initable_new_valist_async

pub unsafe extern "C" fn g_async_initable_new_valist_async(
    object_type: GType,
    first_property_name: *const gchar,
    var_args: va_list,
    io_priority: c_int,
    cancellable: *mut GCancellable,
    callback: GAsyncReadyCallback,
    user_data: gpointer,
)