}

var errDuplicateTagKey = Errorf("Duplicate Tag Keys are not allowed")

// isEmpty returns true if Tags field is null
func (a And) isEmpty() bool {
	return len(a.Tags) == 0 && a.Prefix == ""
}

// Validate - validates the And field
func (a And) Validate() error {
	if a.ContainsDuplicateTag() {
		return errDuplicateTagKey
	}
	for _, t := range a.Tags {