// If no auth scheme avaialble yet, try to initialize it preemptively
if (authState.getAuthScheme() == null) {
AuthScheme authScheme = (AuthScheme) context.getAttribute(
"preemptive-auth");
CredentialsProvider credsProvider = (CredentialsProvider) context.getAttribute(
ClientContext.CREDS_PROVIDER);
HttpHost targetHost = (HttpHost) context.getAttribute(
ExecutionContext.HTTP_TARGET_HOST);
if (authScheme != null) {
Credentials creds = credsProvider.getCredentials(
new AuthScope(
targetHost.getHostName(),
targetHost.getPort()));
if (creds == null) {
throw new HttpException("No credentials for preemptive authentication");