@Test
// tests concatenation of single EMPTY Population
public void testConcatenate4() throws Exception {

    SimplePopulation pop1 = new SimplePopulation();
    Individual[] indOut = PopulationUtils.concatenate(new Population[]{pop1}, new SimplePopulationFactory()).getIndividuals();
    assertTrue(pop1.getIndividuals() == indOut || indOut.length == 0);
}