NullPointerException while rendering checkbox

[deep26]

I am trying to add a Checkbox to my EditorTreeGrid, but I get this exception on Tree render :

java.lang.NullPointerException: null
at com.extjs.gxt.ui.client.widget.grid.CheckColumnConfig.getCheckState(CheckColumnConfig.java:86)

The column for which I want the checkbox I have declared as :


CheckColumnConfig size = new CheckColumnConfig("genre", "Genre", 100);
CellEditor checkBoxEditor = new CellEditor(new CheckBox());
size.setEditor(checkBoxEditor);
configs.add(size);


In my Model I am setting boolean true or boolean false for this column. The following is an example of how I am doing this :


new Music("Six String Quartets", "Beethoven", true)


Please help me in getting rid of this exception.
Thanks in advance

[fother]

debug your code.. and see what attribute really need for dont return a null pointer.. so set it