anchor.diff:  // hard coded document namespace
   let wb = "http://www.worldbank.org"
   
  +/// unsafe helper functions, should rely on option values
  +
   let xattr s (el:XElement) = el.Attribute(XName.Get(s)).Value
   
   let xelem s (el:XContainer) = el.Element((XName.Get(s,wb)))
  
positive.code: open System.Web
  open System.IO
  open System.Net
  
negative.code:     use response = response
      let stream = response.GetResponseStream ()
      use reader = new StreamReader (stream)
      return!  reader.AsyncReadToEnd() (* method extension via FSharp.PowerPack *) }
  
  let worldBankUrl (functions, props) =
      seq { yield "http://api.worldbank.org"
  