if (QueryFieldConfig.SCORE_FIELD.equals(field) || QueryFieldConfig.DOC_SCORE_FIELD.equals(field)) {
            return SortBuilders.scoreSort().order(order);
        }
        return SortBuilders.fieldSort(field).order(order);
    }

    protected boolean isSearchField(final String field) {
        for (final String searchField : getQueryFieldConfig().searchFields) {
            if (searchField.equals(field)) {

        if (QueryFieldConfig.SCORE_FIELD.equals(field) || QueryFieldConfig.DOC_SCORE_FIELD.equals(field)) {
            return SortBuilders.scoreSort().order(order);
        }
        return SortBuilders.fieldSort(field).order(order);
    }

    public void setHighlightPrefix(final String highlightPrefix) {
        this.highlightPrefix = highlightPrefix;
    }

    public String getHighlightPrefix() {

                            flist.toArray(new FunctionScoreQueryBuilder.FilterFunctionBuilder[flist.size()]))
                    .boostMode(CombineFunction.MULTIPLY));
            reader.addSort(SortBuilders.fieldSort(fessConfig.getIndexFieldClickCount()));
            reader.addSort(SortBuilders.scoreSort());
            return reader;
        }, docPerReq, () -> {
            systemHelper.calibrateCpuLoad();

        assertObjectNotNull("field", field);
        if (fieldSortBuilderList == null) {
            fieldSortBuilderList = new ArrayList<>();
        }
        fieldSortBuilderList.add(SortBuilders.fieldSort(field).order(ascOrDesc ? SortOrder.ASC : SortOrder.DESC));
    }

    // ===================================================================================

        assertObjectNotNull("field", field);
        if (fieldSortBuilderList == null) {
            fieldSortBuilderList = new ArrayList<>();
        }
        fieldSortBuilderList.add(SortBuilders.fieldSort(field).order(ascOrDesc ? SortOrder.ASC : SortOrder.DESC));
    }

    // ===================================================================================

        assertObjectNotNull("field", field);
        if (fieldSortBuilderList == null) {
            fieldSortBuilderList = new ArrayList<>();
        }
        fieldSortBuilderList.add(SortBuilders.fieldSort(field).order(ascOrDesc ? SortOrder.ASC : SortOrder.DESC));
    }

    // ===================================================================================

                    final String[] values = s.split(":");
                    if (values.length > 1) {
                        return SortBuilders.fieldSort(values[0]).order("desc".equalsIgnoreCase(values[0]) ? SortOrder.DESC : SortOrder.ASC);
                    }
                    return SortBuilders.fieldSort(values[0]).order(SortOrder.ASC);
                }).toArray(n -> new SortBuilder[n]));
                ot = OptionalThing.of(sortBuilders);