id property
ID is the assertion's content digest — SHA-256 over every semantic field, rendered hex — computed server-side and never supplied. It is the key a redelivery collapses onto, and it is the id the hold op names.
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? id;