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: updates.go
    path of file: ./repos/sliver/client/version
    
    the code of the file until where you have to start completion: package version

import (
	"encoding/json"
	"errors"
	"io"
	"net/http"
	"os"
	"strconv"
	"strings"
	"time"
)

const (
	skipCheckEnv = "SLIVER_NO_UPDATE_CHECK"
	dateLayout   = "2006-01-02T15:04:05Z"
)

var (
	// GithubReleasesURL - Check this Github releases API for updates
	GithubReleasesURL string
)

// Release - A single Github release object
// https://developer.github.com/v3/repos/releases/
type Release struct {
	ID          int     `json:"id"`
	Name        string  `json:"name"`
	URL         string  `json:"url"`
	HTMLURL     string  `json:"html_url"`
	TagName     string  `json:"tag_name"`
	Body        string  `json:"body"`
	Prerelease  bool    `json:"prerelease"`
	TarballURL  string  `json:"tarball_url"`
	ZipballURL  string  `json:"zipball_url"`
	CreatedAt   string  `json:"created_at"`
	PublishedAt string  `json:"published_at"`
	Assets      []Asset `json:"assets"`
}

// Asset - Asset from a release
// https://developer.github.com/v3/repos/releases/
ty
    
func CheckForUpdates(client *http.Client, prereleases bool) (*Release, error) {
	skip := os.Getenv(skipCheckEnv)
	if skip != "" || GithubReleasesURL == "" {
		return nil, nil
	}

	if client == nil {
		client = &http.Client{}
	}

	resp, err := client.Get(GithubReleasesURL)
	if err != nil {
		return nil, err
	}
	defer resp.Body.Close()
	body, err := io.ReadAll(resp.Body)
	if err != nil {
		return nil, err
	}
	if resp.StatusCode != 200 {
		return nil, errors.New("API returned non-200 status code")
	}
	releases := &[]*Release{}
	err = json.Unmarshal(body, releases)
	if err != nil {
		return nil, err
	}

	mySemVer := SemanticVersion()
	for _, release := range *releases {
		if release.Prerelease && !prereleases {
			continue
		}
		releaseSemVer := parseGitTag(release.TagName)
		for index, myVer := range mySemVer {
			if index < len(releaseSemVer) {
				if releaseSemVer[index] == myVer {
					continue
				}
				if releaseSemVer[index] < myVer {
					break
				}
				if myVer < releaseSemVer[index] {
					return release, nil
				}
			}
		}
	}
	return nil, nil
}