code: @Override
      public CreateStackInstancesResult createStackInstances(CreateStackInstancesRequest request) {
          request = beforeClientExecution(request);
          return executeCreateStackInstances(request);
      }
docs: <p>
  Creates stack instances for the specified accounts, within the specified regions. A stack instance refers to a
  stack in a specific account and region. <code>Accounts</code> and <code>Regions</code> are required
  parameters—you must specify at least one account and one region.
  </p>
  
  @param createStackInstancesRequest
  @return Result of the CreateStackInstances operation returned by the service.
  @throws StackSetNotFoundException
  The specified stack set doesn't exist.
  @throws OperationInProgressException
  Another operation is currently in progress for this stack set. Only one operation can be performed for a
  stack set at a given time.
  @throws OperationIdAlreadyExistsException
  The specified operation ID already exists.
  @throws StaleRequestException
  Another operation has been performed on this stack set since the specified operation was performed.
  @throws InvalidOperationException
  The specified operation isn't valid.
  @throws LimitExceededException
  The quota for the resource has already been reached.</p>
  <p>
  For information on resource and stack limitations, see <a
  href="https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/cloudformation-limits.html"
  >Limits</a> in the <i>AWS CloudFormation User Guide</i>.
  @sample AmazonCloudFormation.CreateStackInstances
  @see <a href="http://docs.aws.amazon.com/goto/WebAPI/cloudformation-2010-05-15/CreateStackInstances"
  target="_top">AWS API Documentation</a>