private TestCloseable(@Nullable Throwable throwOnClose) {
      this.throwOnClose = throwOnClose;
    }

    public boolean isClosed() {
      return closed;
    }

    @Override
    public void close() throws IOException {
      closed = true;
      if (throwOnClose != null) {
        throwIfInstanceOf(throwOnClose, IOException.class);
        throwIfUnchecked(throwOnClose);

    private TestCloseable(@Nullable Throwable throwOnClose) {
      this.throwOnClose = throwOnClose;
    }

    public boolean isClosed() {
      return closed;
    }

    @Override
    public void close() throws IOException {
      closed = true;
      if (throwOnClose != null) {
        throwIfInstanceOf(throwOnClose, IOException.class);
        throwIfUnchecked(throwOnClose);