code: public void touchFile(@NotNull final Transaction txn, @NotNull final File file) {
          new LastModifiedTrigger(txn, file, pathnames).run();
      }
docs: Touches the specified {@linkplain File}, i.e. sets its {@linkplain File#getLastModified() last modified time} to
  current time.
  
  @param txn  {@linkplain Transaction} instance
  @param file {@linkplain File} instance
  @see #readFile(Transaction, File)
  @see #readFile(Transaction, long)
  @see #readFile(Transaction, File, long)
  @see #writeFile(Transaction, File)
  @see #writeFile(Transaction, long)
  @see #writeFile(Transaction, File, long)
  @see #writeFile(Transaction, long, long)
  @see #appendFile(Transaction, File)
  @see File#getLastModified()