code: func apiVersionValid(c *vim25.Client, minVersionString string) error {
  	if minVersionString == "-" {
  		// Disable version check
  		return nil
  	}
  
  	apiVersion := c.ServiceContent.About.ApiVersion
  	if isDevelopmentVersion(apiVersion) {
  		return nil
  	}
  
  	realVersion, err := ParseVersion(apiVersion)
  	if err != nil {
  		return fmt.Errorf("error parsing API version %q: %s", apiVersion, err)
  	}
  
  	minVersion, err := ParseVersion(minVersionString)
  	if err != nil {
  		return fmt.Errorf("error parsing %s=%q: %s", envMinAPIVersion, minVersionString, err)
  	}
  
  	if !minVersion.Lte(realVersion) {
  		err = fmt.Errorf("require API version %q, connected to API version %q (set %s to override)",
  			minVersionString,
  			c.ServiceContent.About.ApiVersion,
  			envMinAPIVersion)
  		return err
  	}
  
  	return nil
  }
docs: // apiVersionValid returns whether or not the API version supported by the
  // server the client is connected to is not recent enough.