public void produce(RuleEvaluation e, int offset) {
        PhraseItem newPhrase = new PhraseItem();
        newPhrase.setIndexName(getLabel());
        for (String term : terms)
            newPhrase.addItem(new WordItem(term, true));

        Match matched = e.getNonreferencedMatch(0);
        insertMatch(e, matched, List.of(newPhrase), offset);
    }
Returns a read only view of the terms produced by this, never null
container-search/src/main/java/com/yahoo/prelude/semantics/rule/LiteralPhraseProduction.java