public IEnumerable <Product> Filter(IEnumerable <Product> items, BaseSpecification <Product> specification)
{
foreach (var item in items)
{
if (specification.IsSutisfied(item))
{
yield return(item);
}
}
}
public override bool IsSutisfied(T item)
{
return(_first.IsSutisfied(item) && _second.IsSutisfied(item));
}