Like g_dbus_proxy_call() but also takes a gio.UnixFDList object.
This method is only available on UNIX.
Name of method to invoke.
A glib.Variant tuple with parameters for the signal or NULL if not passing parameters.
Flags from the GDBusCallFlags enumeration.
The timeout in milliseconds (with G_MAXINT meaning "infinite") or -1 to use the proxy default timeout.
A gio.UnixFDList or NULL.
A gio.Cancellable or NULL.
A GAsyncReadyCallback to call when the request is satisfied or NULL if you don't care about the result of the method invocation.
The data to pass to callback.