Result of an availability check against the remote feed.
Either version may be null when unknown (e.g. nothing installed yet, or the manifest could not be reached).
null
Whether the feed offers a newer version than what is installed.
The installed version, or null when nothing is cached.
The latest version advertised by the feed, or null when unknown.
Result of an availability check against the remote feed.
Remarks
Either version may be
nullwhen unknown (e.g. nothing installed yet, or the manifest could not be reached).