for (int l = nextPermutation.size() - 1; l > j; l--) {
        if (comparator.compare(ak, nextPermutation.get(l)) < 0) {
          return l;
        }
      }
      throw new AssertionError("this statement should be unreachable");
    }
  }

  /**
   * Returns a {@link Collection} of all the permutations of the specified {@link Collection}.
   *

      for (int l = nextPermutation.size() - 1; l > j; l--) {
        if (comparator.compare(ak, nextPermutation.get(l)) < 0) {
          return l;
        }
      }
      throw new AssertionError("this statement should be unreachable");
    }
  }

  /**
   * Returns a {@link Collection} of all the permutations of the specified {@link Collection}.
   *