@Override
        public boolean removeAll(Collection<?> c) {
            boolean anyRemoved = false;
            for (Object field : c)
                if (remove(field))
                    anyRemoved = true;
            return anyRemoved;
        }
The computed set of fields. Lazily created as it is not always needed.
container-search/src/main/java/com/yahoo/prelude/fastsearch/FastHit.java