code: public static File mkdirs(File file) throws IOException, IllegalArgumentException
    {
      Params.notNull(file, "File");
      File parentFile = file.getParentFile();
      if(parentFile != null && !parentFile.exists() && !file.getParentFile().mkdirs()) {
        throw new IOException(String.format("Fail to create target file |%s| directories.", file.getAbsolutePath()));
      }
      return file;
    }
docs: Create all ancestor directories for a requested file path. Given <code>file</code> is assumed to be a file path,
  not a directory; this method retrieve file parent and enact {@link File#mkdirs()}. If given file reside into file
  system root this method does nothing.
  <p>
  For caller convenience this method returns <code>file</code> argument, see sample usage.
  
  <pre>
  save(text, new FileWriter(Files.mkdirs(file)));
  </pre>
  
  @param file file path.
  @return given file argument with guaranteed parent directories.
  @throws IOException if directories creation fails.
  @throws IllegalArgumentException if <code>file</code> parameter is null.