Return the next node after the end of this bucket, or 0 if 0 == last(), so the range to traverse to traverse all nodes in the bucket is always [ first(), end() )] regardless of whether the bucket is empty.
0 == last()
[ first(), end() )]
Declared in <bslalg_hashtablebucket.h>
<bslalg_hashtablebucket.h>
BidirectionalLink* end() const;