Files.write(data, temp);
    assertThat(Files.toByteArray(temp)).isEqualTo(data);

    assertThrows(NullPointerException.class, () -> Files.write(null, temp));
  }

  public void testAppendString() throws IOException {
    File temp = createTempFile();
    Files.append(I18N, temp, UTF_16LE);
    assertThat(Files.toString(temp, UTF_16LE)).isEqualTo(I18N);
    Files.append(I18N, temp, UTF_16LE);