anchor.diff:      /// <returns>
       ///     A multiset containing the given items.
       /// </returns>
  -    let ofFlatList xs =
  -        xs |> List.toSeq |> ofFlatSeq
  +    let ofFlatList (xs : List<_>) =
  +        xs |> ofFlatSeq
   
       /// <summary>
       ///     Creates a multiset with one item.
  
positive.code:     /// <returns>
      ///     A singleton multiset.
      /// </returns>
      let singleton x = ofFlatList [ x ]
  
  
      (*
  
negative.code: /// </typeparam>
  type Multiset<'item> when 'item: comparison =
      | MSet of Map<'item, int>
      override this.ToString() = sprintf "%A" this
  /// <summary>
  ///     Operations on multisets.
  /// </summary>
  