* Each time when we try to associate this <code>TreeGrid</code> with some parent (during parsing
* and refresh), we ensure that we have <code>ColumnConfig</code> with
* <code>TreeGridCellRenderer</code>.
*/
private void ensureTreeColumn_directlyBeforeAssociation() {
addBroadcastListener(new EvaluationEventListener() {
@Override
public void evaluateBefore(EvaluationContext context, ASTNode node) throws Exception {
if (isPossibleAssociation(node)) {
ensureTreeColumn();
}