short firstKey = getKeyAtIndex(0);
MappeableContainer container = getContainerAtIndex(0);
return firstKey << 16 | container.first();
}
@Override
<BUG>public int last() {
if(size == 0) {
return 0;
}</BUG>
short lastKey = getKeyAtIndex(size - 1);

short firstKey = getKeyAtIndex(0);
MappeableContainer container = getContainerAtIndex(0);
return firstKey << 16 | container.first();
}
@Override
public int last() {
assertNonEmpty();
short lastKey = getKeyAtIndex(size - 1);
