public static Bill makeBill(final IceCreamOrder order) {
    int nbBalls = order.getBalls().values().stream().mapToInt(Integer::intValue).sum();
    Float price = PRICES.get(nbBalls) + order.getMixins().size() * MIXIN_PRICE;
    return new Bill(price);
  }
Makes a bill from an order.

@param order ice cream order
@return bill
vertx/feign-vertx/src/test/java/feign/vertx/testcase/domain/Bill.java