internal virtual void DoPrevSetBit(BitArray a, LongBitSet b)
{
int aa = a.Count + Random().Next(100);
long bb = aa;
do
{
aa = a.PrevSetBit(aa-1);
aa--;
while ((aa >= 0) && (!a.Get(aa)))
{
aa--;
}
if (b.Length() == 0)
{
bb = -1;
}
else if (bb > b.Length() - 1)
{
bb = b.PrevSetBit(b.Length() - 1);
}
else if (bb < 1)
{
bb = -1;
}
else
{
bb = bb >= 1 ? b.PrevSetBit(bb - 1) : -1;
}
Assert.AreEqual(aa, bb);
} while (aa >= 0);
}