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