This callback will be run when emit() is called.
Optionaloptions: ConnectOptionsConfigure options for the connection
Unsubscribe from this signal with the original callback instance. While you can use this method, the SignalConnection returned by connect() will not be updated!
The callback you passed to connect().
Disconnect all handlers from this signal event.
ProtectedemitThe number of connections on this signal.
true if this signal has connections.
Subscribe to this signal.