code: func (x *XForwarded) ServeHTTP(w http.ResponseWriter, r *http.Request) {
  	if !x.insecure && !x.isTrustedIP(r.RemoteAddr) {
  		for _, h := range xHeaders {
  			r.Header.Del(h)
  		}
  	}
  
  	x.rewrite(r)
  
  	x.next.ServeHTTP(w, r)
  }
docs: // ServeHTTP implements http.Handler