Function gio_sys::g_async_initable_new_async

pub unsafe extern fn g_async_initable_new_async(object_type: GType,
                                                io_priority: c_int,
                                                cancellable: *mut GCancellable,
                                                callback: GAsyncReadyCallback,
                                                user_data: gpointer,
                                                first_property_name: *const c_char,
                                                ...)