anchor.diff:      let x2 = Newtonsoft.Json.JsonConvert.DeserializeObject<HashSet<R>> json
       #endif
       (0, x2) ||> Seq.fold (fun acc v -> acc + v.i) |> equal 3
  +
  +
  
positive.code:     xs.Count |> equal 1
          
  
  
  [<Test>]
  let ``HashSet creation works``() =
  
negative.code: [<Test>]
  let ``HashSet.Add works``() =
      let hs = HashSet<_>()
      hs.Add("A", "Hello") |> equal true
      hs.Add("B", "World!") |> equal true
      hs.Count |> equal 2
  
  [<Test>]
  let ``HashSet.Clear works``() =
      let hs = HashSet<_>()
      hs.Add("A", 1) |> equal true
      hs.Add("B", 2) |> equal true
      hs.Clear()
      hs.Count |> equal 0
  
  [<Test>]
  let ``HashSet.Contains works``() =
      let hs = HashSet<_>()
      hs.Add("Hello") |> equal true
      hs.Add("World!") |> equal true
      hs.Contains("Hello") |> equal true
      hs.Contains("Everybody!") |> equal false
  
  