On the client-side, this signal is emitted whenever the D-Bus signal <link linkend="gdbus-signal-org-freedesktop-ModemManager1-Modem.
StateChanged">"StateChanged"</link> is received.
On the service-side, this signal can be used with e.g. emit_by_name to make the object emit the D-Bus signal.
| arg_old |
Argument. |
| arg_new |
Argument. |
| arg_reason |
Argument. |