public static collection <T> getInstance()
{
if (instance == null)
{
instance = new collection <T>();
}
return(instance);
}
public collection <T> Merge(collection <T> second)
{
collection <T> table = new collection <T>();
foreach (var oneitem in second.getItems())
{
if (!(this.attend(oneitem)))
{
table.addItem(oneitem);
}
}
return(table);
}