public boolean retainAll(ShortIterable source)
{
int oldSize = this.size();
final ShortSet sourceSet = source instanceof ShortSet ? (ShortSet) source : source.toSet();
ShortIntHashMap retained = ShortIntHashMap.this.select(new ShortIntPredicate()
{
public boolean accept(short key, int value)
{
return sourceSet.contains(key);
}