Connectivity constructor
Connectivity()
Constructs a singleton instance of Connectivity.
Connectivity is designed to work as a singleton.
Implementation
// When a second instance is created, the first instance will not be able to listen to the
// EventChannel because it is overridden. Forcing the class to be a singleton class can prevent
// misuse of creating a second instance from a programmer.
factory Connectivity() {
if (_singleton == null) {
_singleton = Connectivity._();
}
return _singleton!;
}