invalidPartNumber:  true,
			accessKey:          credentials.AccessKey,
			secretKey:          credentials.SecretKey,
			expectedRespStatus: http.StatusOK,
		},
		// Test case - 13.
		// maximum part number.
		{
			bucketName:         bucketName,
			uploadID:           uploadID,

		return false
	}

	switch c {
	case '-', '_', '.', '/', '*':
		return false
	}
	return true
}

// s3URLEncode is based on Golang's url.QueryEscape() code,
// while considering some S3 exceptions:
//   - Avoid encoding '/' and '*'
//   - Force encoding of '~'
func s3URLEncode(s string) string {
	spaceCount, hexCount := 0, 0
	for i := range len(s) {
		c := s[i]

						PrincipalID: "test-user",
					},
				}, nil
			}

			body := []byte{}
			req := httptest.NewRequest("GET", "/objectlambda/"+bucketName+"/"+objectName+"?lambdaArn="+url.QueryEscape(lambdaARN), bytes.NewReader(body))
			req.Form = url.Values{"lambdaArn": []string{lambdaARN}}
			req.Header.Set("Host", "localhost")
			req.Header.Set("X-Amz-Date", time.Now().UTC().Format("20060102T150405Z"))

	signature := getSignature(signingKey, stringToSign)

	req.URL.RawQuery = query.Encode()

	// Add signature header to RawQuery.
	req.URL.RawQuery += "&X-Amz-Signature=" + url.QueryEscape(signature)

	// Construct the final presigned URL.
	return nil
}

// preSignV2 - presign the request in following style.

	c.Assert(err, nil)
	// setting the "X-Amz-Copy-Source" to allow copying the content of previously uploaded object.
	request.Header.Set("X-Amz-Copy-Source", url.QueryEscape(SlashSeparator+bucketName+SlashSeparator+objectName))
	if s.signer == signerV4 {
		err = signRequestV4(request, s.accessKey, s.secretKey)
	} else {
		err = signRequestV2(request, s.accessKey, s.secretKey)
	}