code: func (c *Client) TorrentGet(fields []string, ids []int64) (torrents []*Torrent, err error) {
  	// Validate fields
  	var fieldInvalid bool
  	var knownField string
  	for _, inputField := range fields {
  		fieldInvalid = true
  		for _, knownField = range validTorrentFields {
  			if inputField == knownField {
  				fieldInvalid = false
  				break
  			}
  		}
  		if fieldInvalid {
  			err = fmt.Errorf("field '%s' is invalid", inputField)
  			return
  		}
  	}
  	// Forward to real method
  	return c.torrentGet(fields, ids)
  }
docs: // TorrentGet returns the given of fields (mandatory) for each ids (optionnal).
  // https://github.com/transmission/transmission/blob/2.9x/extras/rpc-spec.txt#L144