code: @Override
      public AddListenerCertificatesResult addListenerCertificates(AddListenerCertificatesRequest request) {
          request = beforeClientExecution(request);
          return executeAddListenerCertificates(request);
      }
docs: <p>
  Adds the specified certificate to the specified HTTPS listener.
  </p>
  <p>
  If the certificate was already added, the call is successful but the certificate is not added again.
  </p>
  <p>
  To list the certificates for your listener, use <a>DescribeListenerCertificates</a>. To remove certificates from
  your listener, use <a>RemoveListenerCertificates</a>. To specify the default SSL server certificate, use
  <a>ModifyListener</a>.
  </p>
  
  @param addListenerCertificatesRequest
  @return Result of the AddListenerCertificates operation returned by the service.
  @throws ListenerNotFoundException
  The specified listener does not exist.
  @throws TooManyCertificatesException
  You've reached the limit on the number of certificates per load balancer.
  @throws CertificateNotFoundException
  The specified certificate does not exist.
  @sample AmazonElasticLoadBalancing.AddListenerCertificates
  @see <a href="http://docs.aws.amazon.com/goto/WebAPI/elasticloadbalancingv2-2015-12-01/AddListenerCertificates"
  target="_top">AWS API Documentation</a>