SpigotMC/BungeeCord — pull request #1170 by minecrafter (2014-08-16 23:06:23+00:00)
Title: Finalize the ServerDisconnectEvent target field.

There is no good reason for it to be mutable in the first place, considering that the event instance is not used after the method is called.

Pulling this would do a great service to my plugin RedisBungee that would rely on its immutablity.