code: function (other) {
          assertNotNull(other);
  
          var c = collectionCount(other);
  
          if (c !== -1) {
              // if other is the empty set then this is a superset
              if (c === 0) {
                  return true;
              }
  
              else if (areEqualityComparersEqual(this, other)) {
                  if (c > this.count()) {
                      return false;
                  }
              }
          }
  
          return containsAllElements(this, other);
      }
docs: Determines whether the current set is a superset of a specified collection.
  @param {Iterable} other The collection to compare to the current set.
  @returns {Boolean}