public void RegisterExtension(IWebSocketMessageExtension extension)
        {
            if (_isReadOnly)
            {
                throw new WebSocketException("Extensions cannot be added after the service is started");
            }

            _extensions = _extensions ?? new Dictionary <string, IWebSocketMessageExtension>();
            _extensions.Add(extension.Name.ToLowerInvariant(), extension);
        }
 internal bool TryGetExtension(string name, out IWebSocketMessageExtension extension)
 {
     extension = null;
     return(_extensions == null ? false : _extensions.TryGetValue(name, out extension));
 }