anchor.diff:      someTran conn
       Assert.AreEqual(0L, countUsers conn)
   
  -[<Test>]
  -
  +[<Test;Parallelizable>]
   let ``transaction with exception`` () =
       withDatabase (fun conn ->
           let conn = Sql.withConnection conn
  
positive.code:         all |> Seq.truncate 10 |> Seq.iter (fun r -> printfn "name: %s" (r?name).Value)
      assertThrows<InvalidOperationException> secondIter
  
  [<Test>]
  
  let ``datareader to seq is forward-only``() =
      withDatabase (fun conn ->
          let conn = Sql.withConnection conn
  
negative.code:     // try to divide n by 2..max (stops when divisor is found)
      not ({ 2..max } |> Seq.filter (fun d -> n%d = 0) |> Enumerable.Any)
  
  [<Test;Parallelizable>]
  let ``pseq isprime`` () =
      let p = {100000..800000}
              |> PSeq.filter isPrime
  