code: public static FileValue fileValue(File file){
      String contentType = MimetypesFileTypeMap.getDefaultFileTypeMap().getContentType(file);
      return new FileValueBuilderImpl(file.getName()).file(file).mimeType(contentType).create();
    }
docs: Shortcut for calling {@code Variables.fileValue(name).file(file).mimeType(type).create()}.
  The name is set to the file name and the mime type is detected via {@link MimetypesFileTypeMap}.