treeViewer = new TreeViewer( tree );
treeViewer.setUseHashlookup( true );
treeViewer.setColumnProperties( COLUMNS );
ICellModifier cellModifier = new GrantsAndDenialsCellModifier();
treeViewer.setCellModifier( cellModifier );
CellEditor[] cellEditors = new CellEditor[]
{ null, new CheckboxCellEditor( tree ), null };
treeViewer.setCellEditors( cellEditors );