You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: url_technology_fingerprinter.go
    path of file: ./repos/aquatone/agents
    
    the code of the file until where you have to start completion: package agents

import (
	"bytes"
	"encoding/json"
	"fmt"
	"os"
	"regexp"

	"github.com/PuerkitoBio/goquery"
	"github.com/michenriksen/aquatone/core"
)

type FingerprintRegexp struct {
	Regexp *regexp.Regexp
}

type Fingerprint struct {
	Name               string            `json:"name"`
	Categories         []string          `json:"categories"`
	Implies            []string          `json:"implies"`
	Website            string            `json:"website"`
	Headers            map[string]string `json:"headers"`
	HTML               []string          `json:"html"`
	Script             []string
    
func (a *URLTechnologyFingerprinter) OnURLResponsive(url string) {
	a.session.Out.Debug("[%s] Received new responsive URL %s\n", a.ID(), url)
	page := a.session.GetPage(url)
	if page == nil {
		a.session.Out.Error("Unable to find page for URL: %s\n", url)
		return
	}

	a.session.WaitGroup.Add()
	go func(page *core.Page) {
		defer a.session.WaitGroup.Done()
		seen := make(map[string]struct{})
		fingerprints := append(a.fingerprintHeaders(page), a.fingerprintBody(page)...)
		for _, f := range fingerprints {
			if _, ok := seen[f.Name]; ok {
				continue
			}
			seen[f.Name] = struct{}{}
			page.AddTag(f.Name, "info", f.Website)
			for _, impl := range f.Implies {
				if _, ok := seen[impl]; ok {
					continue
				}
				seen[impl] = struct{}{}
				for _, implf := range a.fingerprints {
					if impl == implf.Name {
						page.AddTag(implf.Name, "info", implf.Website)
						break
					}
				}
			}
		}
	}(page)
}