in lib/src/server_handler.dart [47:57]
FutureOr<Response> _onRequest(Request request) {
if (_server._closeMemo.hasRun) {
throw StateError('Request received after the server was closed.');
}
if (_server._handler != null) return _server._handler!(request);
// Avoid async/await so that the common case of a handler already being
// mounted doesn't involve any extra asynchronous delays.
return _server._onMounted.then((_) => _server._handler!(request));
}