public boolean retainAll(ByteIterable source)
{
int oldSize = this.size();
final ByteSet sourceSet = source instanceof ByteSet ? (ByteSet) source : source.toSet();
CharByteHashMap retained = CharByteHashMap.this.select(new CharBytePredicate()
{
public boolean accept(char key, byte value)
{
return sourceSet.contains(value);
}