c.Assert(response.StatusCode, http.StatusOK)

	// retrieve the info of last modification time of the object from the response header.
	lastModified := response.Header.Get("Last-Modified")
	// Parse it into time.Time structure.
	t, err := time.Parse(http.TimeFormat, lastModified)
	c.Assert(err, nil)

	// make HTTP request to obtain object info.