import java.util.concurrent.CompletableFuture;
import java.util.function.Supplier;

public class Ambiguous3 { 
    public CompletableFuture<?> test() { 
        return ok(() -> System.out.append("aaa")); 
    } 
    public <T> CompletableFuture<T> ok(Supplier<T> action) { 
        return CompletableFuture.supplyAsync(action); 
    } 
    public <T> CompletableFuture<T> ok(T body) { 
        return CompletableFuture.completedFuture(body); 
    } 
    public CompletableFuture<Void> ok(Runnable action) { 
        return CompletableFuture.runAsync(action); 
    } 
}