* @throws IOException if an I/O error occurs, or the stream does not support skipping
   */
  public static void skipFully(InputStream in, long n) throws IOException {
    long skipped = skipUpTo(in, n);
    if (skipped < n) {
      throw new EOFException(
          "reached end of stream after skipping " + skipped + " bytes; " + n + " bytes expected");
    }
  }

  /**