code: @Override
      public CheckDNSAvailabilityResult checkDNSAvailability(CheckDNSAvailabilityRequest request) {
          request = beforeClientExecution(request);
          return executeCheckDNSAvailability(request);
      }
docs: <p>
  Checks if the specified CNAME is available.
  </p>
  
  @param checkDNSAvailabilityRequest
  Results message indicating whether a CNAME is available.
  @return Result of the CheckDNSAvailability operation returned by the service.
  @sample AWSElasticBeanstalk.CheckDNSAvailability
  @see <a href="http://docs.aws.amazon.com/goto/WebAPI/elasticbeanstalk-2010-12-01/CheckDNSAvailability"
  target="_top">AWS API Documentation</a>