func stack404()  { var buf [404]byte; use(buf[:]); C.callGoStackCheck() }
func stack408()  { var buf [408]byte; use(buf[:]); C.callGoStackCheck() }
func stack412()  { var buf [412]byte; use(buf[:]); C.callGoStackCheck() }
func stack416()  { var buf [416]byte; use(buf[:]); C.callGoStackCheck() }
func stack420()  { var buf [420]byte; use(buf[:]); C.callGoStackCheck() }

    assertCached(false, 408)
    assertCached(false, 409)
    // the HTTP spec permits caching 410s, but the RI doesn't.
    assertCached(true, 410)
    assertCached(false, 411)
    assertCached(false, 412)
    assertCached(false, 413)
    assertCached(true, 414)
    assertCached(false, 415)
    assertCached(false, 416)
    assertCached(false, 417)
    assertCached(false, 418)
    assertCached(false, 500)

// If-Unmodified-Since - Return the object only if it has not been modified since the specified time, else return a 412 (precondition failed).
func (s *TestSuiteCommon) TestHeadOnObjectLastModified(c *check) {
	// generate a random bucket name.
	bucketName := getRandomBucketName()
	// HTTP request to create the bucket.