promotion.setId(promotionId);
Money newBudget = new Money();
newBudget.setMicroAmount(2000000L);
promotion.setBudget(newBudget);
Promotion[] mutatedPromotions = promotionService.mutate(
new PromotionOperation[] {new PromotionOperation(Operator.SET, null, promotion)});
System.out.printf("Promotion ID %d for business ID %d now has budget micro amount %,d%n",
promotionId, businessId, mutatedPromotions[0].getBudget().getMicroAmount());