func (a And) Validate() error {
	// > This is used in a Lifecycle Rule Filter to apply a logical AND to two or more predicates.
	// ref: https://docs.aws.amazon.com/AmazonS3/latest/API/API_LifecycleRuleAndOperator.html
	// i.e, predCount >= 2
	var predCount int
	if a.Prefix.set {
		predCount++
	}
	predCount += len(a.Tags)
	if a.ObjectSizeGreaterThan > 0 {
		predCount++
	}
	if a.ObjectSizeLessThan > 0 {
		predCount++