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: trace.go
    path of file: ./repos/gccrs/libgo/go/net/http/httptrace
    
    the code of the file until where you have to start completion: // Copyright 2016 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

// Package httptrace provides mechanisms to trace the events within
// HTTP client requests.
package httptrace

import (
	"context"
	"crypto/tls"
	"internal/nettrace"
	"net"
	"net/textproto"
	"reflect"
	"time"
)

// unique type to prevent assignment.
type clientEventContextKey struct{}

// ContextClientTrace returns the ClientTrace associated with the
// provided context. If none, it returns nil.
func ContextClientTrace(ctx context.Context) *ClientTrace {
	trace, _ := ctx.Value(clientEventContextKey{}).(*ClientTrace)
	return trace
}

// WithClientTrace returns a new context based on the provided parent
// c
    
func WithClientTrace(ctx context.Context, trace *ClientTrace) context.Context {
	if trace == nil {
		panic("nil trace")
	}
	old := ContextClientTrace(ctx)
	trace.compose(old)

	ctx = context.WithValue(ctx, clientEventContextKey{}, trace)
	if trace.hasNetHooks() {
		nt := &nettrace.Trace{
			ConnectStart: trace.ConnectStart,
			ConnectDone:  trace.ConnectDone,
		}
		if trace.DNSStart != nil {
			nt.DNSStart = func(name string) {
				trace.DNSStart(DNSStartInfo{Host: name})
			}
		}
		if trace.DNSDone != nil {
			nt.DNSDone = func(netIPs []any, coalesced bool, err error) {
				addrs := make([]net.IPAddr, len(netIPs))
				for i, ip := range netIPs {
					addrs[i] = ip.(net.IPAddr)
				}
				trace.DNSDone(DNSDoneInfo{
					Addrs:     addrs,
					Coalesced: coalesced,
					Err:       err,
				})
			}
		}
		ctx = context.WithValue(ctx, nettrace.TraceKey{}, nt)
	}
	return ctx
}