code: func (d *ResourceDiff) GetChangedKeysPrefix(prefix string) []string {
  	keys := make([]string, 0)
  	for k := range d.diff.Attributes {
  		if strings.HasPrefix(k, prefix) {
  			keys = append(keys, k)
  		}
  	}
  	return keys
  }
docs: // GetChangedKeysPrefix helps to implement Resource.CustomizeDiff
  // where we need to act on all nested fields
  // without calling out each one separately