anchor.diff:  HeaderRow groupingHeader = grid.prependHeaderRow();
   HeaderCell namesCell = groupingHeader.join(
       groupingHeader.getCell("firstname"),
  -    groupingHeader.getCell("lastname"))
  -        .setText("Person");
  +    groupingHeader.getCell("lastname"));
   HeaderCell yearsCell = groupingHeader.join(
       groupingHeader.getCell("born"),
       groupingHeader.getCell("died"),
  -    groupingHeader.getCell("lived"))
  -        .setText("Dates of Life");
  +    groupingHeader.getCell("lived"));
   ----
   
   
  
positive.code: === Hiding Columns
  
  Columns can be hidden by removing them with [methodname]#removeColumn()#. You
  can remove all columns with [methodname]#removeAllColumns()#. The removed columns
  are only removed from the grid, not from the container data source.
  
  To restore a previously removed column, you can call [methodname]#addColumn()#
  
negative.code: 
  Grid supports line-based editing, where double-clicking a row opens the row
  editor. In the editor, the input fields can be edited, as well as navigated with
  Tab and ShiftTab keys. The editor has a [guibutton]#Save# button that commits
  the data item to the container data source and closes the editor. If validation
  fails, an error is displayed and the user can correct the inputs. A
  [guibutton]#Cancel# button discards the changes and exits the editor.
  
  To enable editing, you need to call [methodname]#setEditorEnabled(true)# for the
  grid.
  