anchor.diff:  
   
   [<Test>]
  -let ``interleave should interleave two sequences``() =
  +let ``AsyncSeq.interleave``() =
     let s1 = AsyncSeq.ofSeq ["a";"b";"c"]
     let s2 = AsyncSeq.ofSeq [1;2;3]
     let merged = AsyncSeq.interleave s1 s2 |> AsyncSeq.toList |> Async.RunSynchronously
  
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]
  