@Override
        public boolean remove(Object o) {
            String field = (String)o;
            boolean removed = hit.removeField(field) != null;
            if (fieldSet != null)
                fieldSet.remove(field);
            return removed;
        }
The computed set of fields. Lazily created as it is not always needed.
container-search/src/main/java/com/yahoo/prelude/fastsearch/FastHit.java