Referer-parser Golang：生产设置而不是使用占位符值？

referer-parser read placeholder value in the example, while the production setting is not documented.

I need referer-parser to read real referer value instead of placeholder value.

Below is my code (the referer_url read placeholder value):

package main

import (
    "github.com/labstack/echo"
    "github.com/snowplow/referer-parser/go"
    "net/http"
)

func main() {
    e := echo.New()

    referer_url := "http://www.google.com/search?q=gateway+oracle+cards+denise+linn&hl=en&client=safari"
    r := refererparser.Parse(referer_url)

    e.Get("/users", func(c *echo.Context) *echo.HTTPError {
        return c.String(http.StatusOK, "The search term is: "+r.SearchTerm)
    })

    e.Run(":4444")
}

Read the value you want from the http headers inside your handler:

e.Get("/users", func(c *echo.Context) *echo.HTTPError {
    refererURL := c.Request.Header.Get("Referer")
    r := refererparser.Parse(refererURL)
    return c.String(http.StatusOK, "The search term is: "+r.SearchTerm)
})