public UniVocityFixedDataFormat setFieldLengths(int[] fieldLengths) {
        this.fieldLengths = fieldLengths;
        return this;
    }
@Test
    public void shouldConfigureNullValue() {
        UniVocityFixedDataFormat dataFormat = new UniVocityFixedDataFormat()
                .setFieldLengths(new int[] { 1, 2, 3 })
                .setNullValue("N/A");

        assertEquals("N/A", dataFormat.getNullValue());
        assertEquals("N/A", dataFormat.createAndConfigureWriterSettings().getNullValue());
        assertEquals("N/A", dataFormat.createAndConfigureParserSettings().getNullValue());
    }