ror;

        const svg = d3.select('#chart3'),
            width = +svg.attr('width'),
            height = +svg.attr('height');

        let link = svg.selectAll('line')
            .data(graph.links)
            .enter().append('line');

        link
            .attr('class', 'link')
                        // hidding the link can be done here, by changing the opacity to 0
                        .attr("opacity", 0)
            .style("stroke", "#000")
            .style("stroke-width", "3px")

        