code: @Override
      public  String appendRemoteFileExtension(final String filepath, final String fileext) {
          if (null == fileext) {
              return filepath;
          }
          String result = filepath;
          String ext = fileext;
          if (!ext.startsWith(".")) {
              ext = "." + fileext;
          }
          result += (filepath.endsWith(ext) ? "" : ext);
          return result;
      }
docs: @return a string with a file extension appended if it is not already on the file path
  provided.
  
  @param filepath the file path string
  @param fileext  the file extension, if it does not start with a "." one will be prepended
  first. If null, the unmodified filepath will be returned.