code: private void findNext(
                           DeleteStack    stack)
      {
          if (_last1.key() == null)
              throw new RuntimeException("Help!  In findNext(), _last1.key() == null");
  
          if ( !_eof )
              findNextBeforeEof(stack);
          else
              findNextAfterEof(stack);
      }
docs: Find the next key in the index.
  
  <p>If _eof is false the iterator has not reached the end of the
  index and we can move forward in the normal way.  But if _eof is
  true then the iterator has hit the end of the index and has lost
  its position.  In this case we have to search the index for a key
  that is greater than the last one returned iff the index has
  changed since the last call to next().  If the index has not
  changed then no keys have been added and the iterator is still
  stuck at the end of the index.</p>
  
  <p>On return the information about the found entry (if any) is
  stored in _current1.</p>
  
  @param stack The stack to use to record the traversal.