anchor.diff:  
   class _ServerDbUser implements QueryExecutorUser {
     final ServerImplementation _server;
  -
  -  @override
  -  int schemaVersion = 0;
  -
  -  _ServerDbUser(this._server); // will be overridden by client requests
  +  final DriftCommunication connection;
  +  @override
  +  final int schemaVersion;
  +
  +  _ServerDbUser(this._server, this.connection, this.schemaVersion);
   
     @override
     Future<void> beforeOpen(
         QueryExecutor executor, OpeningDetails details) async {
       final id = _server._putExecutor(executor, beforeCurrent: true);
       try {
  -      await _server._anyClient!.request(RunBeforeOpen(details, id));
  +      await connection.request(RunBeforeOpen(details, id));
       } finally {
         _server._releaseExecutor(id);
       }
  
positive.code: 
    final Map<int, QueryExecutor> _managedExecutors = {};
    int _currentExecutorId = 0;
  
    final Map<int, CancellationToken> _cancellableOperations = {};
  
  
negative.code:     return done;
    }
  
    dynamic _handleRequest(DriftCommunication comms, Request request) {
      final payload = request.payload;
  
      if (payload is NoArgsRequest) {
  