anchor.diff:  open System.Text
   open System.Data
   open System.Collections.Generic
  +open System.IO
  +open System.Threading.Tasks
   open System.Data.SqlClient
   open Microsoft.FSharp.Reflection
   open Microsoft.SqlServer.TransactSql.ScriptDom
  -open System.IO
   
   let DbNull = box DBNull.Value
   
  
positive.code:         use reader = cmd.ExecuteReader()
  
          while reader.Read() do
              let user_type_id = reader.toOption<int> "user_type_id"
              let system_type_id = reader.["system_type_id"] |> unbox<int>
              yield { 
                  Column.Name = string reader.["name"]
  
negative.code:                                 cmd.Connection <- this
                                  use reader = cmd.ExecuteReader()
                                  while reader.Read() do 
                                      let user_type_id = reader |> SqlDataReader.getOption "user_type_id"
                                      let stid = reader.["system_type_id"] |> unbox<byte> |> int
                                      yield {
                                          Column.Name = string reader.["name"]
  