func newReader(ctx context.Context, src io.Reader, size int64, md5Hex, sha256Hex string, actualSize int64, disableMD5 bool, forceMD5 []byte) (*Reader, error) {
	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 {

		// Test case - 12.
		// Input to replicate Md5 mismatch.
		{
			bucketName: bucket, objName: object, uploadID: uploadID, PartID: 1, inputMd5: "d41d8cd98f00b204e9800998ecf8427f",
			expectedError: hash.BadDigest{ExpectedMD5: "d41d8cd98f00b204e9800998ecf8427f", CalculatedMD5: "d41d8cd98f00b204e9800998ecf8427e"},
		},
		// Test case - 13.
		// When incorrect sha256 is provided.
		{

	},
	ErrAccessDenied: {
		Code:           "AccessDenied",
		Description:    "Access Denied.",
		HTTPStatusCode: http.StatusForbidden,
	},
	ErrBadDigest: {
		Code:           "BadDigest",
		Description:    "The Content-Md5 you specified did not match what we received.",
		HTTPStatusCode: http.StatusBadRequest,
	},
	ErrEntityTooSmall: {
		Code:           "EntityTooSmall",