While working on an e$-$commerce service,you need to build a simple aggregator for a report,which will hold sold products and a sum of their prices converted to EUR currency. You're given a stream$($java$.$util.stream.Stream$)$ of SoldProduct objects.SoldProduct is defined as follows: @Value class SoldProduct $\{$ String name; Bigdecimal price; String currency; $\}($@Value comes from lombok tool and will make this class immutable$-$generate toString,equals and hashcode, make all fields private and final,add getters for all the fields and add single all arguments contructor$).$ Write a function,Which will map the Stream to an instance of SoldProductsAggregate which is defined as follows: @Value class SoldProductsAggregate $\{$ List products; BigDecimal total; $\}$ and SimpleSoldProduct @Value class SimpleSoldProduct $\{$ String name; BigDecimal price; $\}$ To convert price to EUR use EURExchangeService which implements ExchangeService: interface ExchangeService $\{$ Optional rate$($String currency$)$; $\}$ Unfortunately EURExchangeService is a bit buggy and may be return some invalid values$($like null,empty or negative$).$ You should handle it by ignoring them. If an argumemt you get as input to SoldProductsAggregates.aggregate$()$ is null,empty Stream and so on$-$thenyou must not return null.In case of such argument, you must convert it to empty Stream before doing the mapping.