code: func (agent *ecsAgent) initializeResourceFields(credentialsManager credentials.Manager) {
  	agent.resourceFields = &taskresource.ResourceFields{
  		Control: cgroup.New(),
  		ResourceFieldsCommon: &taskresource.ResourceFieldsCommon{
  			IOUtil:             ioutilwrapper.NewIOUtil(),
  			ASMClientCreator:   asmfactory.NewClientCreator(),
  			SSMClientCreator:   ssmfactory.NewSSMClientCreator(),
  			CredentialsManager: credentialsManager,
  		},
  		Ctx:              agent.ctx,
  		DockerClient:     agent.dockerClient,
  		NvidiaGPUManager: gpu.NewNvidiaGPUManager(),
  	}
  }
docs: // initializeResourceFields exists mainly for testing doStart() to use mock Control
  // object