What is @Delegate used for?

@Delegate (experimental) generates wrapper methods on a class that forward calls to a field's methods, implementing the composition-based delegation pattern without hand-writing a pass-through method for every method you want to expose.

public class SortedList {
    @Delegate
    private final List<String> items = new ArrayList<>();
}
//  SortedList now exposes add(), remove(), size(), etc. - all forwarded to `items`
//  without SortedList itself implementing List or writing any pass-through methods

This gives you composition's flexibility (you're not locked into extending a specific class, and you can selectively expose only some of the delegate's interface) while avoiding the tedium of manually writing a forwarding method for every single method on the delegated type — particularly valuable when delegating to an interface with many methods, like List or Map.

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