@Override
    public void fill(Result result, String summaryClass, Execution execution) {
        execution.fill(result, summaryClass);
        IndexFacts indexFacts = execution.context().getIndexFacts();
        if (indexFacts.hasNGramIndices())
            recombineNGrams(result.hits().deepIterator(), indexFacts.newSession(result.getQuery()));
    }
Handles NGram indexes by splitting query terms to them into grams and combining summary field values
from such fields into the original text.
<p>
This declares it must be placed after Juniper searchers because it assumes Juniper token separators
(which are returned on bolding) are not replaced by highlight tags when this is run (and "after" means
"before" from the point of view of the result).

@author bratseth
container-search/src/main/java/com/yahoo/search/querytransform/NGramSearcher.java