test.go

package main

import (
    "context"
    "log"
    "net/http"
    "time"
)

func main() {
    srv := &http.Server{Addr: ":443", Handler: http.HandlerFunc(handle)}
    go func() {
        srv.ListenAndServeTLS("chain.pem", "key.pem")
    }()

    time.Sleep(2000 * time.Millisecond)
    srv.Shutdown(context.Background())
}

func handle(w http.ResponseWriter, r *http.Request) {
    log.Printf("Got connection: %s", r.Proto)
    time.Sleep(5000 * time.Millisecond)
    w.WriteHeader(200)
}