code: public RAMFile add(String name, String content)
    {
      try
      {
        return add(name, content.getBytes("UTF-8"));
      }
      catch(UnsupportedEncodingException e)
      {
        // should not happen
        throw new RuntimeException(e);
      }
    }
docs: Creates a file with the content and add it to the directory with this name
  
  @param name
  @param content as a string
  @return the created file