public virtual void AuthFailed(HttpHost authhost, AuthScheme authScheme, HttpContext
                                       context)
        {
            Args.NotNull(authhost, "Host");
            Args.NotNull(context, "HTTP context");
            HttpClientContext clientContext = ((HttpClientContext)HttpClientContext.Adapt(context
                                                                                          ));
            AuthCache authCache = clientContext.GetAuthCache();

            if (authCache != null)
            {
                if (this.log.IsDebugEnabled())
                {
                    this.log.Debug("Clearing cached auth scheme for " + authhost);
                }
                authCache.Remove(authhost);
            }
        }