code: func (im *Image) Destroy() {
  	if im.Pixmap != 0 {
  		xproto.FreePixmap(im.X.Conn(), im.Pixmap)
  		im.Pixmap = 0
  	}
  }
docs: // Destroy frees the pixmap resource being used by this image.
  // It should be called whenever the image will no longer be drawn or painted.