code: public static void packEntry(File fileToPack, File destZipFile, final String fileName) {
      packEntry(fileToPack, destZipFile, new NameMapper() {
        public String map(String name) {
          return fileName;
        }
      });
    }
docs: Compresses the given file into a ZIP file.
  <p>
  The ZIP file must not be a directory and its parent directory must exist.
  
  @param fileToPack
  file that needs to be zipped.
  @param destZipFile
  ZIP file that will be created or overwritten.
  @param fileName
  the name for the file inside the archive