static void savePNG(BufferedImage img, File file) ctex {
  File tempFile = new File(file.getPath() + "_temp");
  ImageIO.write(img, "png", mkdirsFor(tempFile));
  file.delete();
  tempFile.renameTo(file);
}

// gotta love convenience & program-smartness
static void savePNG(File file, BufferedImage img) {
  savePNG(img, file);
}