code: function(self, callback) {
    if (self.pool && self.pool.isDestroyed()) {
      self.cursorState.killed = true;
      const err = new MongoNetworkError(
        f('connection to host %s:%s was destroyed', self.pool.host, self.pool.port)
      );
      _setCursorNotifiedImpl(self, () => callback(err));
      return true;
    }
  
    return false;
  }
docs: Validate if the pool is dead and return error