refer method
Implementation
void refer(String target) {
assert(_session != null, 'ERROR(refer): rtc session is invalid!');
ReferSubscriber refer = _session.refer(target)!;
refer.on(EventReferTrying(), (EventReferTrying data) {});
refer.on(EventReferProgress(), (EventReferProgress data) {});
refer.on(EventReferAccepted(), (EventReferAccepted data) {
_session.terminate();
});
refer.on(EventReferFailed(), (EventReferFailed data) {});
}