Need to be able to execute some code whenever a list changes in size as a result of some user action

public class EventGeneratingCollection<T> implements Collection<T> {
 
    private Collection<T> wrapped;
 
    private Collection<ChangeListener> listeners = new LinkedList<ChangeListener>();
 
    public EventGeneratingCollection(Collection<T> wrapped) {
        this.wrapped = wrapped;
    }
 
    public int size() {
        return wrapped.size();
    }
 
    public boolean isEmpty() {
        return wrapped.isEmpty();
    }
 
    public boolean contains(Object o) {
        return wrapped.contains(o);
    }
 
    public Iterator<T> iterator() {
        return wrapped.iterator();
    }
 
    public Object[] toArray() {
        return wrapped.toArray();
    }
 
    public <T> T[] toArray(T[] a) {
        return wrapped.toArray(a);
    }
 
    public boolean add(T t) {
        boolean changed = wrapped.add(t);
        if (changed) {
            fireChangeEvent();
        }
        return changed;
    }
 
    public boolean remove(Object o) {
        boolean changed = wrapped.remove(o);
        if (changed) {
            fireChangeEvent();
        }
        return changed;
    }
 
    public boolean containsAll(Collection<?> c) {
        return wrapped.containsAll(c);
    }
 
    public boolean addAll(Collection<? extends T> c) {
        boolean changed = wrapped.addAll(c);
        if (changed) {
            fireChangeEvent();
        }
        return changed;
    }
 
    public boolean removeAll(Collection<?> c) {
        boolean changed = wrapped.removeAll(c);
        if (changed) {
            fireChangeEvent();
        }
        return changed;
    }
 
    public boolean retainAll(Collection<?> c) {
        boolean changed = wrapped.retainAll(c);
        if (changed) {
            fireChangeEvent();
        }
        return changed;
    }
 
    public void clear() {
        wrapped.clear();
        fireChangeEvent();
    }
 
    public void addChangeListener(ChangeListener listener) {
        listeners.add(listener);
    }
 
    public void removeChangeListener(ChangeListener listener) {
        listeners.remove(listener);
    }
 
    private void fireChangeEvent() {
        for (ChangeListener listener : listeners) {
            listener.stateChanged(new ChangeEvent(this));
        }
    }
}
                                              

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