private static void flatMap0()
    {

        printTitle("Parse MultiMap with flatMap()");
        
        Map<String, List<String>> multiMap = new HashMap<String, List<String>>()
        {
            {
                put("Knuth", asList("The Art of Programming", "Math"));
                put("Bloch", asList("Effective Java", "Java Puzzlers"));
            }
        };

        Set<String> allBooks = multiMap.values().stream()
            .flatMap(books -> books.stream().map(String::toUpperCase))
            .collect(toSet());
        System.out.println(allBooks);
    }