code: @Override
      public DescribeSpotFleetInstancesResult describeSpotFleetInstances(DescribeSpotFleetInstancesRequest request) {
          request = beforeClientExecution(request);
          return executeDescribeSpotFleetInstances(request);
      }
docs: <p>
  Describes the running instances for the specified Spot Fleet.
  </p>
  
  @param describeSpotFleetInstancesRequest
  Contains the parameters for DescribeSpotFleetInstances.
  @return Result of the DescribeSpotFleetInstances operation returned by the service.
  @sample AmazonEC2.DescribeSpotFleetInstances
  @see <a href="http://docs.aws.amazon.com/goto/WebAPI/ec2-2016-11-15/DescribeSpotFleetInstances" target="_top">AWS
  API Documentation</a>