static <A> void addToListWithMaxSize(Collection<A> l, A a, int maxSize) {
  if (l == null || maxSize <= 0) ret;
  synchronized(collectionMutex(l)) {
    int n;
    while ((n = l.size()) >= maxSize) {
      l.remove(0);
      assertEquals(l.size(), n-1);
    }
    l.add(a);
  }
}