anchor.diff:          testCase "sequence doesn't contain repeats in expected" <| fun _ ->
             let format = "Sequence should contain one, two and four"
             let test () =
  -            Expect.distributed [|2; 2|]  <| Map [
  +            Expect.distributed [|2; 2; 4|]  <| Map [
                     (2, 1)
                     (1, 1)
  -                  (4, 1)
  +                  (4, 2)
                   ] <| format
             let msg =
               sprintf "%s.
  
positive.code:         All elements in `expected` ['item', 'number of expected occurances']:
          {[1, 1], [2, 1], [4, 2]}
          Missing elements from `actual` ('item', 'number of missing occurances'):
          * for 1 found 0 of expected 1
          * for 4 found 1 of expected 2
          Extra elements in `actual` ('item', 'number of extra occurances'):
          * for 2 found 2 of expected 1"
                format
  
negative.code:         Missing elements from `actual` ('item', 'number of missing occurances'):
          * for 4 found 0 of expected 1
          Extra elements in `actual` ('item', 'number of extra occurances'):
          {}"
                format
            assertTestFailsWithMsg msg (test, Normal)
  
  