anchor.diff:  
   
   [<Test>]
  -let ``unfoldAsync should generate a sequence``() =
  +let ``AsyncSeq.unfoldAsync``() =
     
     let gen s = 
       if s < 3 then (s,s + 1) |> Some |> async.Return
  
positive.code: 
  
  [<Test>]
  let ``toList should collect the results into an array``() =
    
    let s = asyncSeq {
      yield 1
  
negative.code: 
  
  [<Test>]
  let ``AsyncSeq.concatSeq``() =
    
    let s = asyncSeq {
      yield [1;2]
  