anchor.diff:      |> should equal (
           IntMap.ofList [(5, "5:a"); (3, "3:b")])
   
  -
  -
  -
  -
  -
  -
  +//[<TestCase>]
  +//let filter () : unit =
  +//    Assert.Fail ()
  +//
  +//[<TestCase>]
  +//let choose () : unit =
  +//    Assert.Fail ()
  +//
  +//[<TestCase>]
  +//let iter () : unit =
  +//    Assert.Fail ()
  +//
  +//[<TestCase>]
  +//let iterBack () : unit =
  +//    Assert.Fail ()
  +//
  +//[<TestCase>]
  +//let fold () : unit =
  +//    Assert.Fail ()
  +//
  +//[<TestCase>]
  +//let foldBack () : unit =
  +//    Assert.Fail ()
  +//
  +//[<TestCase>]
  +//let exists () : unit =
  +//    Assert.Fail ()
  +//
  +//[<TestCase>]
  +//let forall () : unit =
  +//    Assert.Fail ()
  +//
  +//[<TestCase>]
  +//let partition () : unit =
  +//    Assert.Fail ()
  +//
  +//[<TestCase>]
  +//let mapPartition () : unit =
  +//    Assert.Fail ()
   
   
   
  
positive.code: 
  [<TestCase>]
  let remove () : unit =
      [(5, "a"); (3, "b")]
      |> IntMap.ofList
      |> IntMap.remove 5
      |> should equal (
          IntMap.singleton 3 "b")
  
      [(5, "a"); (3, "b")]
      |> IntMap.ofList
      |> IntMap.remove 7
      |> should equal (
          IntMap.ofList [(5, "a"); (3, "b")])
  
      (IntMap.empty : IntMap<string>)
      |> IntMap.remove 5
      |> should equal (IntMap.empty : IntMap<string>)
  
  [<TestCase>]
  let map () : unit =
      [(5, "a"); (3, "b")]
  
negative.code: 
  
  [<TestCase>]
  let isEmpty () : unit =
      IntMap.empty
      |> IntMap.isEmpty
  