code: func getWithRestart(d *schema.ResourceData, key string) interface{} {
  	if d.HasChange(key) {
  		log.Printf("[DEBUG] %s: Resource argument %q requires a VM restart", resourceVSphereVirtualMachineIDString(d), key)
  		d.Set("reboot_required", true)
  	}
  	return d.Get(key)
  }
docs: // getWithRestart fetches the resoruce data specified at key. If the value has
  // changed, a reboot is flagged in the virtual machine by setting
  // reboot_required to true.