code: @Override
      public ListStackInstancesResult listStackInstances(ListStackInstancesRequest request) {
          request = beforeClientExecution(request);
          return executeListStackInstances(request);
      }
docs: <p>
  Returns summary information about stack instances that are associated with the specified stack set. You can
  filter for stack instances that are associated with a specific AWS account name or region.
  </p>
  
  @param listStackInstancesRequest
  @return Result of the ListStackInstances operation returned by the service.
  @throws StackSetNotFoundException
  The specified stack set doesn't exist.
  @sample AmazonCloudFormation.ListStackInstances
  @see <a href="http://docs.aws.amazon.com/goto/WebAPI/cloudformation-2010-05-15/ListStackInstances"
  target="_top">AWS API Documentation</a>