@SuppressWarnings("unchecked")
        OptionalThing<SortBuilder[]> ot = (OptionalThing<SortBuilder[]>) propMap.get(QUERY_COLLAPSE_INNER_HITS_SORTS);
        if (ot == null) {
            final String sorts = getQueryCollapseInnerHitsSorts();
            if (StringUtil.isBlank(sorts)) {
                ot = OptionalThing.empty();
            } else {