email property
Email is the shopper's address, for a cart that belongs to someone who has not signed in. It is what a guest checkout and an abandoned-cart follow-up key on. Empty is fine.
Please note: This property should have been non-nullable! Since the specification file does not include a default value (using the "default:" property), however, the generated source code must fall back to having a nullable type. Consider adding a "default:" property in the specification file to hide this note.
Implementation
String? email;