SMART datagrid v.1 > Classes > RowGroupPanel
Pixel unit minimum height of Row grouping panel displayed on the top of grid. 
It will be applied only if specify a value greater than 0. Comparing with height specified greater than 0, the smaller value will be set as the height of panel.
Defaults to 20.
    grid.setOptions({
        rowGroup: {
            panel: {
                minHeight: 25
            }
        }
    });
    grid.setOptions({
        groupPanel: {
            minHeight: 25
        }
    });
    grid.setGroupPanel({
        minHeight: 25
    });
    grid.groupPanel().setMinHeight(25);