set flag LeanMode.

svoid test_LogNArray() {
  test_LogNArray(1000);
}

svoid test_LogNArray(int n) {
  new LogNArray<S> l;
  assertEqualsVerbose(0, l.size());
  for (int i = -1; i < 2; i++) { int _i = i ; assertException(r { l.get(_i) }); }
  l.add("hello");
  assertEqualsVerbose(1, l.size());
  assertException(r { l.get(-1) });
  assertEqualsVerbose("hello", l.get(0));
  assertException(r { l.get(1) });
  
  Random random = predictableRandom();
  
  // n random insertions, complete check
  
  new LS refl;
  l.clear();
  repeat n {
    int i = random(random, l(refl)+1);
    S id = randomID(random);
    print("add " + i + " " + id);
    refl.add(i, id);
    l.add(i, id);
    assertEquals(l(l), l(refl));
  }
  assertEqualsVerbose(l(l), l(refl));
  for i over refl:
    assertEquals(l.get(i), refl.get(i));
    
  // overwriting
  repeat n {
    int i = random(random, l(refl));
    S id = randomID(random);
    print("set " + i + " " + id);
    assertEquals(l.set(i, id), refl.set(i, id));
    assertEquals(l(l), l(refl));
  }
    
  // n random deletions, check after each turn
  repeat n {
    int i = random(random, l(refl));
    print("remove " + i);
    assertEquals(l.remove(i), refl.remove(i));
    assertEqualsVerbose(l(l), l(refl));
    for j over refl:
      assertEquals(l.get(j), refl.get(j));
  }
  
  System.out.println("LogNArray works (tested up to size " + n + ")! :)");
}

static int l(Collection l) { ret l == null ? 0 : l.size(); }
static int l(S s) { ret s == null ? 0 : s.length(); }

static <A> A print(A a) { System.out.println(a); ret a; }

static int random(Random r, int n) {
  return n <= 0 ? 0 : r.nextInt(n);
}

svoid silentException(Throwable e) {}

do not include function add.
do not include function get.
do not include function set.
do not include function remove.

Began life as a copy of #1024414