title: right-click on a d3.js element: how to prevent browser context menu to appear
body: <p>I have some d3.js element plotted, eg:</p>
  
  <pre><code> // draw rectangle 
    svg.selectAll(".rect").append("rect")
          .attr("y", 10)
          .attr("x", 10)
          .attr("height", 5)
          .attr("width", 5)
          .on("contextmenu", function (d, i) {  
      // react on right-clicking
   });
  </code></pre>
  
  <p>and it works fine but also opens browser's context menu. How I can prevent that from happening?</p>