- (void)webView:(WKWebView *)webView didReceiveAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge completionHandler:(void (^)(NSURLSessionAuthChallengeDisposition disposition,
                            NSURLCredential *credential))completionHandler
{
    if ([challenge.protectionSpace.authenticationMethod isEqualToString:NSURLAuthenticationMethodServerTrust])
    {
        [TSKPinningValidator handleChallenge:challenge completionHandler:completionHandler];
    }
    else
    {
        // Handle alternative (non-SSL) authentication
        NSAssert(@"Unsupported authentication method");
        completionHandler(NSURLSessionAuthChallengePerformDefaultHandling, nil);
    }
}