code: public static void readable(final String path, final String message) throws IllegalArgumentException {
          notNullOrEmpty(path, message);
          readable(new File(path), message);
      }
docs: Checks that the specified String is not null or empty and represents a readable file, throws exception if it is empty or
  null and does not represent a path to a file.
  
  @param path The path to check
  @param message The exception message
  @throws IllegalArgumentException Thrown if path is empty, null or invalid