Streams Java8: Flat Map usage

 public static void fetchUsersWhoseAddressIsOne(){

    List<User> users1 = formUsers().stream()
            .filter(employee -> employee.getAddresses().stream()
                    .anyMatch(adr -> adr.getId().startsWith("1")))
            .collect(Collectors.toList());

    System.out.println(users1);
}
public static void flatMapFetchAddresses(){
    List<Address> addresses =
            formUsers().stream()
                    .map(User::getAddresses).flatMap(Collection::stream)
                    .filter(ad -> ad.getId().equals("1")).collect(Collectors.toList());

    System.out.println(addresses);
}