Разбить массив строк на части используя stream

Stream<String> lines = Files.lines(pathFile);

@Test
public void myTest() {
    Stream<String> lines = Stream.of(
            "some row from my file 1",
            "some row from my file 2",
            "some row from my file 3",
            "some row from my file 4",
            "some row from my file 5",
            "some row from my file n",
            "some row from my file 750000"
    );
    lines.parallel()
            .unordered()
            .collect(Collectors.partitioningBy(s -> s == 3).supplier(it -> {
                myParser(it);
            }));
}
 
public void myParser(List<String> myList){
    System.out.println(myList.size()); // split by 3 lines 
}

        ArrayList<String> list = new ArrayList<>();
 
        lines.forEach(it -> {
            list.add(it);
            if (list.size() > 0 && list.size() % 3 == 0) {
                myParser(list);
                list.clear();
            }
        });

public class T30SplitStream {
 
public static void main(String[] args) {
    Stream<String> lines = Stream.of("some row from my file 1", "some row from my file 2",
            "some row from my file 3", "some row from my file 4", "some row from my file 5",
            "some row from my file n", "some row from my file 750000");
    AtomicInteger i = new AtomicInteger(0);
    Map<Integer, List<String>> map = lines.parallel().unordered().map(s -> new Pair(i.incrementAndGet(), s))
            .collect(Collectors.groupingBy(p -> p.i % 3, Collectors.mapping(p -> p.s, Collectors.toList())));
    System.out.println(map);
 
}
 
public static class Pair {
    public final Integer i;
    public final String s;
 
    public Pair(int i, String s) {
        this.i = i;
        this.s = s;
    }
}
}