public void RemoveObserver(IProductObserver observer)
{
if (observer == null)
{
throw new ArgumentNullException(nameof(observer));
}
_observers.Remove(observer);
}
public void RegisterObserver(IProductObserver observer)
{
if (observer == null)
{
throw new ArgumentNullException(nameof(observer));
}
_observers.Add(observer);
}
public virtual void RemoveObserver(IProductObserver observer)
{
observers.Remove(observer);
}
public virtual void AddObserver(IProductObserver observer)
{
observers.Add(observer);
}
