wasSessionReplaced function
True shortly after session-replaced arrived. The disconnect that follows is then expected: no generic
"disconnected" alert, and never an automatic rejoin (which would push the other connection out in turn).
Implementation
bool wasSessionReplaced({Duration within = const Duration(seconds: 15)}) {
final at = _replacedAt;
return at != null && DateTime.now().difference(at) < within;
}