pub unsafe extern "C" fn g_dbus_proxy_call(
proxy: *mut GDBusProxy,
method_name: *const c_char,
parameters: *mut GVariant,
flags: GDBusCallFlags,
timeout_msec: c_int,
cancellable: *mut GCancellable,
callback: GAsyncReadyCallback,
user_data: gpointer,
)