onPluginUpdateDownloaded
public static NightbreakPluginUpdater.ListenerRegistration onPluginUpdateDownloaded(JavaPlugin plugin, Consumer<NightbreakPluginUpdater.PluginUpdateDownload> listener)
Registers a listener that runs after a plugin update passes checksum and plugin-artifact validation and has been atomically placed in Bukkit's update directory.
The listener runs on the updater's asynchronous download thread. It must schedule any Bukkit API work back onto the server thread. Closing the returned registration is idempotent; shutdown also removes it.