boskos/common/common.go
func (ud *UserData) Update(new *UserData) {
	if new == nil {
		return
	}
	new.Range(func(key, value interface{}) bool {
		if value.(string) != "" {
			ud.Store(key, value)
		} else {
			ud.Delete(key)
		}
		return true
	})
}
func (ud *UserData) Update(new *UserData) {
	if new == nil {
		return
	}
	new.Range(func(key, value interface{}) bool {
		if value.(string) != "" {
			ud.Store(key, value)
		} else {
			ud.Delete(key)
		}
		return true
	})
}
// Update updates existing UserData with new UserData.
// If a key as an empty string, the key will be deleted