static void extractFileFromZipFile(File inZip, S fileName, File destFile) ctex {
  ZipFile zip = new ZipFile(inZip);
  try {
    extractFileFromZipFile(zip, fileName, destFile);
  } finally {
    zip.close();
  }
}
    
static void extractFileFromZipFile(ZipFile zip, S fileName, File destFile) ctex {
  ZipEntry entry = zip.getEntry(fileName);
  if (entry == null) fail("File not found in zip: " + zip + " / " + fileName);
  saveStream(zip.getInputStream(entry), destFile);
}

Began life as a copy of #1002031