src/bosh-softlayer-cpi/registry/agent_settings.go
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
}
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
}
// AttachPersistentDisk updates the agent settings in order to add an attached persistent disk.