@Override
    public final boolean enter(String name) {
        if (prefixComponentIndex++ < prefix.size()) return true; // we're in the given prefix, which should not be included in the name
        if ( ! name.isEmpty()) {
            currentPrefixes.push(currentPrefix);
            currentPrefix = cache.append(currentPrefix, name);
        }
        return true;
    }
The current prefix, relative to prefix.
container-search/src/main/java/com/yahoo/search/query/profile/PrefixQueryProfileVisitor.java