protected boolean labelMatches(RuleEvaluation e) {
        FlattenedItem flattenedItem = e.currentItem();
        if (flattenedItem == null) return true;
        TermItem item = flattenedItem.getItem();
        if (item == null) return true;
        return labelMatches(item, e);
    }
Whether the label matches the current item, true if there is no current item
container-search/src/main/java/com/yahoo/prelude/semantics/rule/Condition.java