anchor.diff:  
   type Address = {
       id: int
  -    street: string
  +    street: string option
       city: string
   }
   
  
positive.code:     use reader = Sql.execReader c "select * from person p join address a on a.id = p.address" []
      assertThrows<ArgumentException> (fun () -> reader |> List.ofDataReader |> ignore)
      ()
  
negative.code:         let conn = Sql.withConnection conn
          dataReaderToSeqIsCacheable conn)
  
  [<Test;Ignore("locks the database because it doesn't close the connection")>]
  let ``datareader to seq is cacheable persistent``() =
      dataReaderToSeqIsCacheable (withNewDbFile())
  
  