func (e PartTooSmall) Error() string {
	return fmt.Sprintf("Part size for %d should be at least 5MB", e.PartNumber)
}

// PartTooBig returned if size of part is bigger than the allowed limit.
type PartTooBig struct{}

func (e PartTooBig) Error() string {
	return "Part size bigger than the allowed limit"
}

// InvalidETag error returned when the etag has changed on disk
type InvalidETag struct{}