@Override
    public Object removeField(String name) {
        Object removedValue = super.removeField(name);
        if (removedValue == null)
            removedValue = getSummaryValue(name);

        if (removedValue != null) {
            if (removedFields == null)
                removedFields = new HashSet<>(2);
            removedFields.add(name);
        }

        return removedValue;
    }
Removes a field from this

@return the removed value of the field, or null if none
container-search/src/main/java/com/yahoo/prelude/fastsearch/FastHit.java