* @param out
     *            出力ストリーム
     * @return コピーしたバイト数
     */
    protected static int copyInternal(final InputStream in, final OutputStream out) {
        try {
            final byte[] buf = new byte[DEFAULT_BUF_SIZE];
            int len;
            int amount = 0;
            while ((len = in.read(buf)) != -1) {
                out.write(buf, 0, len);
                amount += len;

     *            同時更新を行うスレッドの推定数
     * @return {@link ConcurrentHashMap}の新しいインスタンス
     * @see ConcurrentHashMap#ConcurrentHashMap(int, float, int)
     */
    public static <K, V> ConcurrentHashMap<K, V> newConcurrentHashMap(final int initialCapacity, final float loadFactor,
            final int concurrencyLevel) {
        return new ConcurrentHashMap<>(initialCapacity, loadFactor, concurrencyLevel);
    }

    /**