issue
The download handle for an issue.
Cheap and idempotent: it does not start anything, and calling it twice for the same issue gives you the same download. Call it to read an issue's download state as much as to change it — an issue that was never downloaded simply reports Item.State.NotDownloaded.
Return
the Item carrying that issue's download state, progress and controls.
Parameters
issueId
the issue to address.