@Test
public void testToString() {

    PredictionsAggregator aggr = (PredictionsAggregator)doubles -> null;
    assertTrue(aggr.toString().length() > 0);
    assertTrue(aggr.toString(true).length() > 0);
    assertTrue(aggr.toString(false).length() > 0);
    WeightedPredictionsAggregator aggregator = new WeightedPredictionsAggregator(new double[] {});
    assertTrue(aggregator.toString().length() > 0);
    assertTrue(aggregator.toString(true).length() > 0);
    assertTrue(aggregator.toString(false).length() > 0);
}