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: thumbnail.go
    path of file: ./repos/learning_tools/minio/minio_thumbnail
    
    the code of the file until where you have to start completion: package main

import (
	"bytes"
	"fmt"
	"github.com/minio/minio-go"
	"github.com/nfnt/resize"
	"image/jpeg"
	"log"
	"strings"
)

var minioClient *minio.Client

func StartMinio() {
	var err error
	// 初使化 minio client对象。
	minioClient, err = minio.New(endpoint, accessKeyID, secretAccessKey, useSSL)
	if err != nil {
	
    
func CheckFileEx(bucket, fileName string) bool {
	objInfo, err := minioClient.StatObject(bucket, fileName, minio.StatObjectOptions{})
	if err != nil {
		if err.Error() != "The specified key does not exist." {
			fmt.Println("[GetFileAndThumbnail] CheckFileEx  bucket", bucket, "fileName", fileName, "err", err)
		}
		return false
	}
	return objInfo.Key != ""
}