//remove this, beacuse invalidate will cause client side rebuild,
//i must reinitial size helper since there are maybe some customized is from client.
//System.out.println(">>>>>>>>>>>remove this");
//removeAttribute(MERGE_MATRIX_KEY);//TODO remove this, for insert column test only
_custColId = new SequenceId(-1,2);
_custRowId = new SequenceId(-1,2);
this.getWidgetHandler().invaliate();
List list = loadWidgetLoaders();
int size = list.size();