default UIColumn findColumnInGroup(String columnKey, ColumnGroup group) {
        if (group == null) {
            return null;
        }

        for (int i = 0; i < group.getChildCount(); i++) {
            UIComponent row = group.getChildren().get(i);
            for (int j = 0; j < row.getChildCount(); j++) {
                UIComponent rowChild = row.getChildren().get(j);
                if (rowChild instanceof Column) {
                    Column column = (Column) rowChild;
                    if (Objects.equals(column.getColumnKey(), columnKey)) {
                        return column;
                    }
                }
                else if (rowChild instanceof Columns) {
                    Columns columns = (Columns) rowChild;
                    List<DynamicColumn> dynamicColumns = columns.getDynamicColumns();
                    for (UIColumn column : dynamicColumns) {
                        if (Objects.equals(column.getColumnKey(), columnKey)) {
                            return column;
                        }
                    }
                }
            }
        }

        return null;
    }
Return each {@link Row} in a Column Group.
@param context  the {@link FacesContext}
@param cg the {@link ColumnGroup} to get
@param skipUnrendered If unrendered components should be skipped
@param callback The callback, which will be invoked for each row. If it returns false, the algorithm will be cancelled
@return false when the algorithm was cancelled
primefaces/src/main/java/org/primefaces/component/api/ColumnAware.java