Adds a user to the discussion moderator list.
The added ID will not be validated, ie. adding an invalid, non-negative id will both be acceptable and retrievable upon calling GetModeratorIDs. The user who creates a discussion is not added automatically as its moderator.
| Exception Type | Condition |
|---|---|
| InvalidOperationException | The object has not yet been stored or has already been removed. |
| ArgumentException | The userID is not positive. |
IDiscussion Interface | Plumtree.Remote.PRC.Collaboration.Discussion Namespace