@Override
    public java.util.concurrent.Future<ListFirewallDomainListsResult> listFirewallDomainListsAsync(ListFirewallDomainListsRequest request) {

        return listFirewallDomainListsAsync(request, null);
    }
Returns the executor service used by this client to execute async requests.

@return The executor service used by this client to execute async requests.
aws-java-sdk-route53resolver/src/main/java/com/amazonaws/services/route53resolver/AmazonRoute53ResolverAsyncClient.java