code: int specialFind(int startPos, int position)
    {
            // We have to look all the way up the ancestor chain
            // to make sure we don't have an ancestor.
            int ancestor = startPos;
            while(ancestor > 0)
            {
                  // Get the node whose index == ancestor
                  ancestor*=slotsize;
                  int chunkpos = ancestor >> lowbits;
                  int slotpos = ancestor & lowmask;
                  int[] chunk = chunks.elementAt(chunkpos);
                                                          
                  // Get that node's parent (Note that this assumes w[1]
                  // is the parent node index. That's really a DTM feature
                  // rather than a ChunkedIntArray feature.)
                  ancestor = chunk[slotpos + 1];
  
                  if(ancestor == position)
                           break;
            }
  
            if (ancestor <= 0) 
            {
                    return position;
            }
            return -1;
    }
docs: This test supports DTM.getNextPreceding.