CredentialsProvider credsProvider = (CredentialsProvider) context.getAttribute(ClientContext.CREDS_PROVIDER);
HttpHost targetHost = (HttpHost) context.getAttribute(ExecutionContext.HTTP_TARGET_HOST);
// If not auth scheme has been initialized yet
if (authState.getAuthScheme() == null) {
AuthScope authScope = new AuthScope(targetHost.getHostName(), targetHost.getPort());
// Obtain credentials matching the target host
Credentials creds = credsProvider.getCredentials(authScope);
// If found, generate BasicScheme preemptively