code: int findAndFill(RowCursor cursor)
    {
      int ptr = find(cursor);
  
      if (ptr >= 0) {
        cursor.setRow(_buffer, ptr);
        cursor.setLeafBlock(this, ptr);
      }
      
      return ptr;
    }
docs: Searches for a row matching the cursor's key in the block.
  If the key is found, fill the cursor with the row.