code: void fillDeltaEntries(Set<PageLeafEntry> entries,
                          Row row,
                          int tail)
    {
      int rowOffset = _rowHead;
      
      byte []buffer = _buffer;
  
      while (rowOffset < tail) {
        int code = buffer[rowOffset] & CODE_MASK;
  
        int len = getLength(code, row);
        if (code == INSERT || code == REMOVE) {
          PageLeafEntry entry = new PageLeafEntry(this, row, rowOffset, len, code);
        
          entries.add(entry);
        }
        
        rowOffset += len;
      }
    }
docs: Fill the entry set from the tree map.