public DecimalFormat decimalFormat() {
        return decimalFormat;
    }
@Test
    public void shouldBeCaseInsensitiveForDecimalFormatConfig() {
        final Map<String, Object> configValues = new HashMap<>();
        configValues.put(ConverterConfig.TYPE_CONFIG, ConverterType.KEY.getName());
        configValues.put(JsonConverterConfig.DECIMAL_FORMAT_CONFIG, "NuMeRiC");

        final JsonConverterConfig config = new JsonConverterConfig(configValues);
        assertEquals(config.decimalFormat(), DecimalFormat.NUMERIC);
    }