Want: r.contentHash.Encoded,
					Got:  base64.StdEncoding.EncodeToString(sum),
				}
				return n, err
			}
		}
	}
	if err != nil && err != io.EOF {
		if v, ok := err.(etag.VerifyError); ok {
			return n, BadDigest{
				ExpectedMD5:   v.Expected.String(),
				CalculatedMD5: v.Computed.String(),
			}
		}
	}
	return n, err
}