MD5, err := hex.DecodeString(md5Hex)
	if err != nil {
		return nil, BadDigest{ // TODO(aead): Return an error that indicates that an invalid ETag has been specified
			ExpectedMD5:   md5Hex,
			CalculatedMD5: "",
		}
	}
	SHA256, err := hex.DecodeString(sha256Hex)
	if err != nil {

		inputReaderData string
		inputMd5        string
		inputSHA256     string
		inputDataSize   int64
		// flag indicating whether the test should pass.
		shouldPass bool
		// expected error output.
		expectedMd5   string
		expectedError error
	}{
		// Test case  1-4.
		// Cases with invalid bucket name.
		{bucketName: ".test", objName: "obj", PartID: 1, expectedError: fmt.Errorf("%s", "Bucket name invalid: .test")},