Represents a topic referenced in the join path. This feature is used when you use Defined Join Paths to customize join preferences on the Joins tab of Data Model options.
This example shows how to add all topics to the join path:
Documents["Sample 1.bqy"].Sections["SalesQuery"].DataModel.JoinOptions.DefinedJoinPaths["JoinPath1"].AddAllTopics()
AddAllTopics, AddTopic(DefinedJoinPathsName as String), Remove(), RemoveAllTopics(), RemoveTopic(DefinedJoinPathName as String)