@Override
  public String formatDouble(Locale locale, Double value) {
    NumberFormat format = DecimalFormat.getNumberInstance(locale);
    format.setMinimumFractionDigits(1);
    format.setMaximumFractionDigits(1);
    return format.format(value);
  }
@Test
  public void format_double() {
    assertThat(underTest.formatDouble(Locale.FRENCH, 10.56)).isEqualTo("10,6");
    assertThat(underTest.formatDouble(Locale.FRENCH, 10d)).isEqualTo("10,0");
  }