Url rewrite - access value in a Golang plugin post trigger validation?

Here’s a minimal example to log the rewritten path. It needs to be called from the ‘post’ middleware hook.

package main

import (
        "log"
        "net/http"
        "github.com/TykTechnologies/tyk/ctx"
        "github.com/davecgh/go-spew/spew"
)

// LogUrlRewriteTarget logs the final rewrite target
func LogUrlRewriteTarget(rw http.ResponseWriter, r *http.Request) {
  if v := r.Context().Value(ctx.UrlRewriteTarget) ; v != nil {
    log.Println(v)
  } else {
    log.Println("No Rewrite")
  }
}

func main() {}