@Override public FieldValue applyTo(FieldValue fval) { if (fval instanceof Array) { Array array = (Array) fval; FieldValue element = array.getFieldValue(((IntegerFieldValue) value).getInteger()); element = update.applyTo(element); array.set(((IntegerFieldValue) value).getInteger(), element); } else if (fval instanceof WeightedSet) { WeightedSet wset = (WeightedSet) fval; WeightedSetDataType wtype = wset.getDataType(); Integer weight = wset.get(value); if (weight == null) { if (wtype.createIfNonExistent() && update instanceof ArithmeticValueUpdate) { weight = 0; } else { return fval; } } weight = (Integer) update.applyTo(new IntegerFieldValue(weight)).getWrappedValue(); wset.put(value, weight); if (wtype.removeIfZero() && update instanceof ArithmeticValueUpdate && weight == 0) { wset.remove(value); } } return fval; }