code: public static <T, U> Collector<T, ?, Seq<T>> modeAllBy(Function<? super T, ? extends U> function) {
          return Collector.of(
              () -> new LinkedHashMap<U, List<T>>(),
              (m, t) -> m.compute(function.apply(t), (k, l) -> {
                  List<T> result = l != null ? l : new ArrayList<>();
                  result.add(t);
                  return result;
              }),
              (m1, m2) -> {
                  for (Entry<U, List<T>> e : m2.entrySet()) {
                      List<T> l = m1.get(e.getKey());
  
                      if (l == null)
                          m1.put(e.getKey(), e.getValue());
                      else
                          l.addAll(e.getValue());
                  }
  
                  return m1;
              },
              m -> Seq.seq(m).maxAllBy(t -> t.v2.size()).flatMap(t -> Seq.seq(t.v2))
          );
      }
docs: Get a {@link Collector} that calculates the <code>MODE()</code> function.