// Presign is not needed for anonymous credentials.
	if accessKeyID == "" || secretAccessKey == "" {
		return errors.New("Presign cannot be generated without access and secret keys")
	}

	// FIXME: Remove following portion of code after fixing a bug in minio-go preSignV2.

	d := UTCNow()
	// Find epoch expires when the request will expire.
	epochExpires := d.Unix() + expires

	// Add expires header if not present.

	}

	err := lockFileEx(fd, flags, 1, 0, &syscall.Overlapped{})
	if err == nil || err == errLockViolation {
		return nil
	}
	if err.Error() == "The process cannot access the file because another process has locked a portion of the file." {
		return ErrAlreadyLocked
	}
	return err
}

func lockFileEx(h syscall.Handle, flags, locklow, lockhigh uint32, ol *syscall.Overlapped) (err error) {
	reserved := uint32(0)