code: func (director *BoshDirector) GetDeploymentManifest(deploymentName string) (manifest io.Reader, err error) {
  	endpoint := fmt.Sprintf("https://%s:%d/deployments/%s", director.ip, director.port, deploymentName)
  	httpEntity := director.getEntity(endpoint, "text/yaml")
  	request := director.gateway.Get(httpEntity)
  	resp, err := request()
  	if err != nil {
  		return
  	}
  	manifest, err = retrieveManifest(resp)
  	return
  }
docs: //GetDeploymentManifest -