version property
Version is the digest of what that publisher supplied, so a refresh that changed nothing can be told from a refresh that did not run.
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? version;