SwiftDocCTutorialReferenceClassTutorialReferenceA reference to a Tutorial or TutorialArticle by URL.final class TutorialReferenceTopicsInstance Propertiesvar originalMarkup: BlockDirectivevar topic: TopicReferenceThe tutorial page or tutorial article to which this refers.Instance Methodsfunc accept<V>(inout V) -> V.ResultType Propertiesstatic let introducedVersion: String