code: final void nextStream() throws IOException {
          if (in != null) {
              in.close();
          }
  
          if (e.hasMoreElements()) {
              in = (InputStream) e.nextElement();
              if (in == null)
                  throw new NullPointerException();
          }
          else in = null;
  
      }
docs: Continues reading in the next stream if an EOF is reached.