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