}
// Optionally, add service unavailable retry executor
final ServiceUnavailableRetryStrategy serviceUnavailStrategy = this.serviceUnavailStrategy;
if (serviceUnavailStrategy != null) {
execChain = new ServiceUnavailableRetryExec(execChain, serviceUnavailStrategy);
}
// Optionally, add connection back-off executor
final BackoffManager backoffManager = this.backoffManager;
final ConnectionBackoffStrategy connectionBackoffStrategy = this.connectionBackoffStrategy;
if (backoffManager != null && connectionBackoffStrategy != null) {