sclass MultiSetAndTopTen<A> {

  int maxEntries = 100000, topTenTargetLength = 10;

  Map<A, Long> ms;

  L<A> topTen;

  Set<A> topTenSet;

  transient Lock lock = lock();

  *() {}

  *(Map<A, Long> *ms, L<A> *topTen) { topTenSet = new TreeSet(topTen); }

  void add(A a) {

    lock lock;

    long count = longMultiSet_add(ms, a);

    insertToTopTen(a, count);

    if (l(ms) >= maxEntries)

      longMultiSet_dropBottomPart(ms, l(ms)-iround(maxEntries*0.9));

  }

  void insertToTopTen(A a, long count) {

    int originalIndex = topTenSet.contains(a) ? indexOf(topTen, a) : -1;

    int i = originalIndex < 0 ? l(topTen) : originalIndex;

    while (i > 0 && count >= toLong(ms.get(topTen.get(i-1)))) // maybe this is even better than binary search as we will usually exit immediately

      --i;

    if (i >= topTenTargetLength || i == originalIndex) ret;

    if (originalIndex >= 0) topTen.remove(originalIndex);

    topTen.add(i, a); topTenSet.add(a);

    while (l(topTen) > topTenTargetLength)

      topTenSet.remove(popLast(topTen));

  }

  void printTopTen {

    printAsciiHeading("TOP TEN (OF " + l(ms) + ")");

    pnl(map(topTen, func(S s) { s + " [" + ms.get(s) + "]" }));

  }

  void setTopTenSize(int size) {

    topTenTargetLength = size;

    if (l(topTen) != size) newTopTen(size);

  }

  void newTopTen(int size) {

    topTenTargetLength = size;

    replaceCollection(topTen, takeFirst(size, sortByDescScore(keys(ms), ms)));

    topTenSet = new TreeSet(topTen);

  }

  int numEntries() { ret l(ms); }

  long numOccurrences() { ret longMultiSet_l(ms); }

  bool contains(A a) { ret ms.containsKey(a); }

  long get(A a) { ret toLong(ms.get(a)); }

  L<A> topTen() { lock lock; ret cloneList(topTen); }

  L<A> entries() { lock lock; ret asList(keys(ms)); }

  void clear { lock lock; ms.clear(); topTen.clear(); topTenSet.clear(); }

}