oneValueAccumulatorByAddAllEmptyStats.addAll(Stats.of());

    twoValuesAccumulator = new StatsAccumulator();
    twoValuesAccumulator.addAll(TWO_VALUES);

    twoValuesAccumulatorByAddAllStats = new StatsAccumulator();
    twoValuesAccumulatorByAddAllStats.addAll(Stats.of(ONE_VALUE));
    twoValuesAccumulatorByAddAllStats.addAll(Stats.of(OTHER_ONE_VALUE));

    emptyAccumulatorByAddAllEmptyPairedStats.addAll(emptyAccumulator.snapshot());

    oneValueAccumulator = new PairedStatsAccumulator();
    oneValueAccumulator.add(ONE_VALUE, OTHER_ONE_VALUE);

    oneValueAccumulatorByAddAllEmptyPairedStats = new PairedStatsAccumulator();
    oneValueAccumulatorByAddAllEmptyPairedStats.add(ONE_VALUE, OTHER_ONE_VALUE);
    oneValueAccumulatorByAddAllEmptyPairedStats.addAll(emptyAccumulator.snapshot());

        final List<String> tagList = new ArrayList<>();
        for (final String tagFieldName : tagFieldNames) {
            tagList.addAll(Arrays.asList(SuggestUtil.parseQuery(queryString, tagFieldName)));
            if (filterQueryString != null) {
                tagList.addAll(Arrays.asList(SuggestUtil.parseQuery(filterQueryString, tagFieldName)));
            }
        }

    emptyAccumulatorByAddAllEmptyPairedStats.addAll(emptyAccumulator.snapshot());

    oneValueAccumulator = new PairedStatsAccumulator();
    oneValueAccumulator.add(ONE_VALUE, OTHER_ONE_VALUE);

    oneValueAccumulatorByAddAllEmptyPairedStats = new PairedStatsAccumulator();
    oneValueAccumulatorByAddAllEmptyPairedStats.add(ONE_VALUE, OTHER_ONE_VALUE);
    oneValueAccumulatorByAddAllEmptyPairedStats.addAll(emptyAccumulator.snapshot());

        assertNotNull(response);
    }

    @Test
    public void test_addRole() throws Exception {
        indexItems();

        PopularWordsResponse response = suggester.popularWords().addRole(SuggestConstants.DEFAULT_ROLE).execute().getResponse();

        assertNotNull(response);
    }

    @Test
    public void test_addField() throws Exception {
        indexItems();

                    fessConfig.getIndexFieldLang());
            // Initialize Set for O(1) lookup performance
            searchFieldSet = new HashSet<>();
            Collections.addAll(searchFieldSet, searchFields);
        }
        if (facetFields == null) {
            facetFields = fessConfig.getQueryAdditionalFacetFields(//
                    fessConfig.getIndexFieldUrl(), //

        assertNotNull(response);
    }

    @Test
    public void test_addRole() throws Exception {
        indexItems();

        SuggestResponse response = suggester.suggest().setQuery("test").addRole(SuggestConstants.DEFAULT_ROLE).execute().getResponse();

        assertNotNull(response);
        assertEquals(1, response.getNum());
    }

    @Test
    public void test_addField() throws Exception {

            return parent.containsAll(c);
        }

        public boolean addAll(final Collection<? extends E> c) {
            return parent.addAll(c);
        }

        public boolean addAll(final int index, final Collection<? extends E> c) {
            return parent.addAll(index, c);
        }

        public boolean removeAll(final Collection<?> c) {

    assertThat(mmHeap.peek()).isNull();
    assertThat(mmHeap.poll()).isNull();
  }

  public void testRemove() {
    MinMaxPriorityQueue<Integer> mmHeap = MinMaxPriorityQueue.create();
    mmHeap.addAll(Lists.newArrayList(1, 2, 3, 4, 47, 1, 5, 3, 0));
    assertTrue("Heap is not intact initially", mmHeap.isIntact());
    assertEquals(9, mmHeap.size());
    mmHeap.remove(5);
    assertEquals(8, mmHeap.size());

            return parent.containsAll(c);
        }

        @Override
        public boolean addAll(final Collection<? extends E> c) {
            return parent.addAll(c);
        }

        @Override
        public boolean addAll(final int index, final Collection<? extends E> c) {
            return parent.addAll(index, c);
        }

        @Override
        public boolean removeAll(final Collection<?> c) {