Challenge: Selecting Random Products Within a Category

Imagine you have a list of products from an online store. Your goal is to group them by category, pick a random product from each group, and display the result.

1. Group the list of products by category using groupingBy().
2. For each category (productList), get the list of products using the stream() method and select a random product with findAny().
3. Check if the Optional contains a value using ifPresent().
4. If Optional has a value, print the information in the following format: "Category: {category} => {product}".