code: @Override
      public RegisterContainerInstanceResult registerContainerInstance(RegisterContainerInstanceRequest request) {
          request = beforeClientExecution(request);
          return executeRegisterContainerInstance(request);
      }
docs: <note>
  <p>
  This action is only used by the Amazon ECS agent, and it is not intended for use outside of the agent.
  </p>
  </note>
  <p>
  Registers an EC2 instance into the specified cluster. This instance becomes available to place containers on.
  </p>
  
  @param registerContainerInstanceRequest
  @return Result of the RegisterContainerInstance operation returned by the service.
  @throws ServerException
  These errors are usually caused by a server issue.
  @throws ClientException
  These errors are usually caused by a client action, such as using an action or resource on behalf of a
  user that doesn't have permissions to use the action or resource, or specifying an identifier that is not
  valid.
  @throws InvalidParameterException
  The specified parameter is invalid. Review the available parameters for the API request.
  @sample AmazonECS.RegisterContainerInstance
  @see <a href="http://docs.aws.amazon.com/goto/WebAPI/ecs-2014-11-13/RegisterContainerInstance" target="_top">AWS
  API Documentation</a>