code: func NewFileName(X *xgbutil.XUtil, fileName string) (*Image, error) {
  	srcReader, err := os.Open(fileName)
  	if err != nil {
  		return nil, err
  	}
  	defer srcReader.Close()
  
  	img, _, err := image.Decode(srcReader)
  	if err != nil {
  		return nil, err
  	}
  	return NewConvert(X, img), nil
  }
docs: // NewFileName uses the image package's decoder and converts a file specified
  // by fileName to an xgraphics.Image value.
  // Opening a file or decoding an image can cause an error.