kind property
Kind is how the baseline comes to exist: fetch (downloaded from a publisher), local (computed here), attest (held by the component that screens against it, freshness reported), or gap (declared and NOT held, because the source needs a licence we do not have).
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? kind;