anchor.diff:          then raise(InvalidOperationException("Could not listen to port " + port, e))
           false
   
  +/// Checks whether the http listener can be bound to the given port.
   let ensureCanBindHttpPort port =
       if not <| canListen port
       then
  
positive.code:     ctx.Response.AddHeader("access-control-allow-headers", "content-type, accept")
      ctx.Response.Close(response, true)
  
  let placeholderRegex = new Regex("{([^}]+)}",RegexOptions.Compiled)
  
  let routeMatcher route =
      let dict = new System.Collections.Generic.Dictionary<int,string>()
  
  
negative.code: 
  let private getStatus args (ctx : HttpListenerContext) = "Http listener is running"
  
  /// Contains the default routes.
  let defaultRoutes =
      [ "GET", "", getStatus] 
  
  /// Creates routes for the http listener.
  let createRoutes routes = 
      routes
      |> Seq.map (fun (verb, route : string, func) ->        
  