anchor.diff:  | Valid of Node
   | Invalid of string * int * string
   
  +type Destination =
  +| Ok of GUID
  +| Error of string * int * string
  +
  +// A function for the resource request func to send requests through
  +// partial_resource_url, method, data -> response
  +type SendFunc = string -> string -> string -> HttpListenerResponse
  +
  +// A function to handle resource requests
  +// context (for replying to this call!), split_path (without /resources), send_func, state -> state
  +type ResourceRequestFunc<'a> = HttpListenerContext -> string list -> SendFunc -> 'a -> 'a
  +
   //type DeliverFunc = string -> GUID -> unit
   //type ForwardFunc = string -> GUID -> GUID -> string * GUID
   //type NewLeafFunc = GUID list -> unit
  
positive.code:             | "pastry"::stuff -> // only handles '/pastry'
                  let error_message = sprintf "Unrecognized pastry request url: '%s'" path
                  Invalid(error_message, 404, "Illegal action")
              | _ ->
                  let error_message = sprintf "Not related to pastry: %s" path
                  Invalid(error_message, 200, "Not found")
  
          match result with
          | Valid(updated_node) ->
              listen updated_node // Listen again
          | Invalid(error_message, status, reason) ->
              error error_message
              reply response error_message status reason
  
      ignore <| listen node // Start listening
  
  // Creates a local node and makes it join the Pastry network
  let join_network (address: NetworkLocation) (peer: NetworkLocation option) =
      let guid = hash address
      printfn "? Pastry GUID: %020d%020d" guid.a guid.b
      let node: Node = {
  
negative.code:                     | "update" ->
                          reply response "Send attempted!" 200 "Ok"
                          Valid(route node Update body guid)
                      | "joinstate" ->
                          reply response "Received!" 200 "Ok"
                          Valid(handle_message node JoinState body guid)
  