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: dial_socketopt.go
    path of file: ./repos/moby/vendor/google.golang.org/api/transport/grpc
    
    the code of the file until where you have to start completion: // Copyright 2019 Google LLC.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

//go:build go1.11 && linux
// +build go1.11,linux

package grpc

import (
	"context"
	"net"
	"syscall"

	"google.golang.org/grpc"
)

const (
	// defaultTCPUserTimeout is the default TCP_USER_TIMEOUT socket option. By
	// default is 20 seconds.
	tcpUserTimeoutMilliseconds = 20000

	// Copied from golang.org/x/sys/unix.TCP_USER_TIMEOUT.
	t
    
func dialTCPUserTimeout(ctx context.Context, addr string) (net.Conn, error) {
	control := func(network, address string, c syscall.RawConn) error {
		var syscallErr error
		controlErr := c.Control(func(fd uintptr) {
			syscallErr = syscall.SetsockoptInt(
				int(fd), syscall.IPPROTO_TCP, tcpUserTimeoutOp, tcpUserTimeoutMilliseconds)
		})
		if syscallErr != nil {
			return syscallErr
		}
		if controlErr != nil {
			return controlErr
		}
		return nil
	}
	d := &net.Dialer{
		Control: control,
	}
	return d.DialContext(ctx, "tcp", addr)
}