Angular js nvd3 set margin for legends

Question

How to add margin to legends for nvd3 charts. I'm following https://github.com/krispo/angular-nvd3/blob/gh-pages/js/lineChart.js they have given events for legends but not shown any example related to legend margins. I have tried like

chart: {
                type: 'lineChart',
                height: 200,
                margin: {
                    top: 20,
                    right: 20,
                    bottom: 40,
                    left: 55
                },
                legend: {
                    margin: {
                        top: 20,
                        right: 20,
                        bottom: 40,
                        left: 55
                    }
                }

} And in html <nvd3 options="options" data="effortData" class="with-3d-shadow with-transitions"></nvd3>

But this is not working. Is there any way to add margin to legends? Thank you.