protected override void IssueToken(IHttpContext httpContext, OAuthRequestContext requestContext)
        {
            // Generate an access token
            IAccessToken accessToken = GenerateToken(TokenType.Access, httpContext, requestContext) as IAccessToken;

            if (accessToken == null)
            {
                throw new InvalidOperationException();
            }

            // Mark the token as authorized
            accessToken.ChangeStatus(TokenStatus.Authorized);

            // Don't store the token
            // Don't mark the request token as used

            // Add to the response
            requestContext.ResponseParameters[OAuthParameterKeys.Token]       = accessToken.Token;
            requestContext.ResponseParameters[OAuthParameterKeys.TokenSecret] = accessToken.Secret;
        }