code: function getInversionOf(comparator) {
      function inversion(a, b) {
          return -comparator(a, b);
      }
  
      inversion.original = comparator;
  
      return inversion;
  }
docs: Inverts the given comparator so the array will be sorted reversed.
  The original comparator is saved so it can be restored.
  
  @private
  @param {Function} comparator
  @returns {Function}