This adds an alternative to OfflinePlayer#isOnline that returns true only if the same instance of the player is still online. This is generally more useful than isOnline as it allows you to determine if you have an instance of a Player that still exists. If a player relogs an old Player instance becomes unlinked leading to e.g. messages sent to the old player no longer arriving despite isOnline returning true. Checking against isConnected is more useful there to discard invalid instances.
Aeltumn