public UniVocityFixedDataFormat setFieldLengths(int[] fieldLengths) {
        this.fieldLengths = fieldLengths;
        return this;
    }
@Test
    public void shouldConfigureEmptyValue() {
        UniVocityFixedDataFormat dataFormat = new UniVocityFixedDataFormat()
                .setFieldLengths(new int[] { 1, 2, 3 })
                .setEmptyValue("empty");

        assertEquals("empty", dataFormat.getEmptyValue());
        assertEquals("empty", dataFormat.createAndConfigureWriterSettings().getEmptyValue());
    }