docs: private void rotateLeft(int n) {
          final int r = right(n);
          final int lr = left(r);
          right(n, lr);
          if (lr != NIL) {
              parent(lr, n);
          }
          final int p = parent(n);
          parent(r, p);
          if (p == NIL) {
              root = r;
          } else if (left(p) == n) {
              left(p, r);
          } else {
              assert right(p) == n;
              right(p, r);
          }
          left(r, n);
          parent(n, r);
          fixAggregates(n);
          fixAggregates(parent(n));
      }