loggedIn property
LoggedIn is always false — this is the answer to having just signed out, so it states the resulting session state rather than reporting the request's outcome. It is not omitempty: false is the whole answer.
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
bool? loggedIn;