public List<AggregationProjection> getAggregationProjections() {
        List<AggregationProjection> result = new LinkedList<>();
        for (Projection each : projections) {
            if (each instanceof AggregationProjection) {
                AggregationProjection aggregationProjection = (AggregationProjection) each;
                result.add(aggregationProjection);
                result.addAll(aggregationProjection.getDerivedAggregationProjections());
            }
        }
        return result;
    }
@Test
    void assertGetAggregationProjections() {
        Projection projection = getAggregationProjection();
        List<AggregationProjection> items = new ProjectionsContext(0, 0, true, Arrays.asList(projection, getColumnProjection())).getAggregationProjections();
        assertTrue(items.contains(projection));
        assertThat(items.size(), is(1));
    }