The module exports a `addObjectSignalMethods()` method that extends
the provided prototype with `connectObject()` and `disconnectObject()`
methods.
In its simplest form, `connectObject()` looks like the regular
`connect()` method, except for an additional parameter:
```js
this._button.connectObject('clicked',
() => this._onButtonClicked(), this);
```
The additional object can be used to disconnect all handlers on the
instance that were connected with that object, similar to
`g_signal_handlers_disconnect_by_data()` (which cannot be used
from introspection).
For objects that are subclasses of Clutter.Actor, that will happen
automatically when the actor is destroyed, similar to
`g_signal_connect_object()`.
Finally, `connectObject()` allows to conveniently connect multiple
signals at once, similar to `g_object_connect()`:
```js
this._toggleButton.connect(
'clicked', () => this._onClicked(),
'notify::checked', () => this._onChecked(), this);
```
Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/1953>
