}
// Optionally, add connection back-off executor
final BackoffManager backoffManager = this.backoffManager;
final ConnectionBackoffStrategy connectionBackoffStrategy = this.connectionBackoffStrategy;
if (backoffManager != null && connectionBackoffStrategy != null) {
execChain = new BackoffStrategyExec(execChain, connectionBackoffStrategy, backoffManager);
}
Lookup<AuthSchemeProvider> authSchemeRegistry = this.authSchemeRegistry;
if (authSchemeRegistry == null) {
authSchemeRegistry = RegistryBuilder.<AuthSchemeProvider>create()