public void setFilter(boolean filter) {
        if (filter) {
            creator = ItemCreator.FILTER;
        } else {
            creator = ItemCreator.ORIG;
        }
    }
Sets whether this is a filter term. Filter terms are treated just like other terms except that
they will not be highlighted in dynamic summaries.
container-search/src/main/java/com/yahoo/prelude/query/Item.java