title: How to create legend for Plotlines with Highstock of Highcharts?
body: <p>I have a Highstock graph with Plotlines here: <a href="http://jsfiddle.net/qd0rmazg/3/" rel="nofollow noreferrer">http://jsfiddle.net/qd0rmazg/3/</a></p>
  
  <p>I'd like to be able to have a legend of Plotlines where, similar to the legend of Series, upon a click Plotlines of a certain category can be made visible or hidden.</p>
  
  <p>In my JSfiddle example, there are 2 categories of Plotlines. Is it possible to toggle the visibility of Plotlines per one category? I couldn't seem to find anything supporting this.</p>
  
  <p>This is how I've created the Plotlines:</p>
  
  <pre><code>xAxis: {
     plotLines: [{
        value: Date.UTC(2016, 12, 29), // year, month, day
        width: 1,
        color: 'blue',
        dashStyle: 'ShortDash',
        label: {
            text: 'Category 1',
        },
     }, {
        value: Date.UTC(2016, 11, 12), // year, month, day
        width: 1,
        color: 'green',
        dashStyle: 'Solid',
        label: {
            text: 'Category 2',
        }]
  }
  </code></pre>