code: func (e *Engine) performCheck() {
  	log.Printf("Checking for updates to Torus")
  
  	latest, err := e.getLatestVersion()
  	if err != nil {
  		log.Printf("Could not retrieve latest version of Tours: %s", err)
  		return
  	}
  
  	e.targetVersion = latest
  	if err := e.storeLastCheck(); err != nil {
  		log.Printf("Cannot store the last check date: %s", err)
  	}
  
  	log.Printf("Successfully checked for updates; available version: %s", latest)
  }
docs: // performCheck retrieves the latest version of Torus from the manifest and then