anchor.diff:      props
   
   let getRaw id rev props = 
  -    request id props
  -    |> querystring (props.converter.ConvertRevToMap rev)
  +    match rev with 
  +    | None -> 
  +        request id props 
  +    | Some rev ->
  +        request id props 
  +        |> querystring (props.converter.ConvertRevToMap rev)
       |> send Get
   
   let get id rev props = 
  
positive.code:     |> Async.Map (props.converter.ReadAsPostPutCopyResponse props.fieldMapping)
  
  let delete id rev props = 
      match rev with 
      | None -> 
          request id props 
      | Some rev -> 
          request id props
          |> querystring (props.converter.ConvertRevToMap rev)
      |> send Delete
      |> Async.Ignore
  
  
negative.code:     |> Async.Map (props.converter.ReadAsPostPutCopyResponse props.fieldMapping)
  
  let update id rev (document: InsertedDocument<'a>) props = 
      props
      |> request id
      |> querystring (props.converter.ConvertRevToMap rev)
      |> body (props.converter.WriteInsertedDocument props.fieldMapping document)
      |> send Put
      |> Async.Map (props.converter.ReadAsPostPutCopyResponse props.fieldMapping)
  