code: @Override
      public DescribeInstanceHealthResult describeInstanceHealth(DescribeInstanceHealthRequest request) {
          request = beforeClientExecution(request);
          return executeDescribeInstanceHealth(request);
      }
docs: <p>
  Describes the state of the specified instances with respect to the specified load balancer. If no instances are
  specified, the call describes the state of all instances that are currently registered with the load balancer. If
  instances are specified, their state is returned even if they are no longer registered with the load balancer.
  The state of terminated instances is not returned.
  </p>
  
  @param describeInstanceHealthRequest
  Contains the parameters for DescribeInstanceHealth.
  @return Result of the DescribeInstanceHealth operation returned by the service.
  @throws LoadBalancerNotFoundException
  The specified load balancer does not exist.
  @throws InvalidInstanceException
  The specified endpoint is not valid.
  @sample AmazonElasticLoadBalancing.DescribeInstanceHealth
  @see <a href="http://docs.aws.amazon.com/goto/WebAPI/elasticloadbalancing-2012-06-01/DescribeInstanceHealth"
  target="_top">AWS API Documentation</a>