code: func (as AgentSettings) AttachPersistentDisk(diskID string, updateSetting []byte) (AgentSettings, error) {
  	persistenDiskSettings := make(map[string]PersistentSettings)
  
  	var persistentSetting PersistentSettings
  	err := json.Unmarshal(updateSetting, &persistentSetting)
  	if err != nil {
  		return as, err
  	}
  
  	persistenDiskSettings[diskID] = persistentSetting
  	as.Disks.Persistent = persistenDiskSettings
  
  	return as, nil
  }
docs: // AttachPersistentDisk updates the agent settings in order to add an attached persistent disk.