@Test
public void testCompareTo() {

    GeneIdentifier first = GeneIdentifier.builder().geneSymbol("1ABC").build();
    GeneIdentifier second = GeneIdentifier.builder().geneSymbol("1BBC").build();
    GeneIdentifier third = GeneIdentifier.builder().geneSymbol("2BCD").build();
    List<GeneIdentifier> geneIdentifiers = Arrays.asList(second, first, third);
    geneIdentifiers.sort(GeneIdentifier::compareTo);
    assertThat(geneIdentifiers, equalTo(Arrays.asList(first, second, third)));
}