Consider the following code:

public interface EventQueue $\{$

public boolean add$($Event e$)$;

public Event peek$()$;

public Event poll$()$;

public boolean isEmpty$()$;

$\}$

Which of the following classes does not properly implement

public class DefaultQueue extends LinkedList$\frac{\frac{?}{?}}{?}\frac{\frac{?}{?}}{?}\frac{\frac{?}{?}}{?}\frac{\frac{?}{?}}{?}$