Parent class of the immutable GuiList and mutable GuiMutableList.
Invokes all listeners, causing all open guis using this list to update.
Provides access to the internal collection in an immutable form. Please do only use the collection inside the block lambda, as only there thread-safety can be guaranteed.
Registers an onChangeListener, which will be called if the content of this list is mutated.
Unregisters an already registered onChangeListener.