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: server_test.go
    path of file: ./repos/minio/cmd
    
    the code of the file until where you have to start completion: // Copyright (c) 2015-2021 MinIO, Inc.
//
// This file is part of MinIO Object Storage stack
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be 
    
func (s *TestSuiteCommon) TestObjectValidMD5(c *check) {
	// generate a random bucket name.
	bucketName := getRandomBucketName()
	// HTTP request to create the bucket.
	request, err := newTestSignedRequest(http.MethodPut, getMakeBucketURL(s.endPoint, bucketName),
		0, nil, s.accessKey, s.secretKey, s.signer)
	c.Assert(err, nil)

	// execute the HTTP request to create bucket.
	response, err := s.client.Do(request)
	c.Assert(err, nil)
	c.Assert(response.StatusCode, 200)

	// Create a byte array of 5MB.
	// content for the object to be uploaded.
	data := bytes.Repeat([]byte("0123456789abcdef"), 5*humanize.MiByte/16)
	// calculate etag of the data.
	etagBase64 := getMD5HashBase64(data)

	buffer1 := bytes.NewReader(data)
	objectName := "test-1-object"
	// HTTP request for the object to be uploaded.
	request, err = newTestSignedRequest(http.MethodPut, getPutObjectURL(s.endPoint, bucketName, objectName),
		int64(buffer1.Len()), buffer1, s.accessKey, s.secretKey, s.signer)
	c.Assert(err, nil)
	// set the Content-Md5 to be the hash to content.
	request.Header.Set("Content-Md5", etagBase64)
	response, err = s.client.Do(request)
	c.Assert(err, nil)
	// expecting a successful upload.
	c.Assert(response.StatusCode, http.StatusOK)
	objectName = "test-2-object"
	buffer1 = bytes.NewReader(data)
	// HTTP request for the object to be uploaded.
	request, err = newTestSignedRequest(http.MethodPut, getPutObjectURL(s.endPoint, bucketName, objectName),
		int64(buffer1.Len()), buffer1, s.accessKey, s.secretKey, s.signer)
	c.Assert(err, nil)
	// set Content-Md5 to invalid value.
	request.Header.Set("Content-Md5", "kvLTlMrX9NpYDQlEIFlnDA==")
	// expecting a failure during upload.
	response, err = s.client.Do(request)
	c.Assert(err, nil)
	// Since Content-Md5 header was wrong, expecting to fail with "SignatureDoesNotMatch" error.
	verifyError(c, response, "SignatureDoesNotMatch", "The request signature we calculated does not match the signature you provided. Check your key and signing method.", http.StatusForbidden)
}