code: func GetStringSlicePreserveString(cfg Provider, key string) []string {
  	sd := cfg.Get(key)
  	if sds, ok := sd.(string); ok {
  		return []string{sds}
  	}
  	return cast.ToStringSlice(sd)
  }
docs: // GetStringSlicePreserveString returns a string slice from the given config and key.
  // It differs from the GetStringSlice method in that if the config value is a string,
  // we do not attempt to split it into fields.