code property
Code is the referrer's referral code, as it appeared in their ?ref= link. Case and surrounding whitespace do not matter.
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? code;