@Override
    public void resolve(MapChoice choice,Query query,Result result,Resolution resolution) {
        Map<String, List<PageElement>> mapping=new HashMap<>();
        // Draw a random element from the value list on each iteration and assign it to a placeholder
        List<String> placeholderIds=choice.placeholderIds();
        List<List<PageElement>> valueList=new ArrayList<>(choice.values());
        for (String placeholderId : placeholderIds)
            mapping.put(placeholderId,valueList.remove(random.nextInt(valueList.size())));
        resolution.addMapChoiceResolution(choice,mapping);
    }
Chooses a mapping which is always by the literal order given in the source template
container-search/src/main/java/com/yahoo/search/pagetemplates/engine/resolvers/RandomResolver.java