title: Using Highcharts styled mode svg patterns not exporting
body: <p>I wonder if anyone has any suggestions with this problem:</p>
  <p>I am using styled mode for Highcharts and defining custom SVG patterns for the chart fills, however when I export the chart as an image it doesn't render the patterns and seems to default to black and white.</p>
  <p>Defining the pattern like this:</p>
  <pre><code>// Define the patterns
  Highcharts.setOptions({
  defs: {
      hatchLeft: {
          tagName: 'pattern',
          id: 'hatch-left',
          etc.
  </code></pre>
  <p>You can see this problem in Highcharts' own example JS Fiddle: <a href="https://jsfiddle.net/gh/get/library/pure/highcharts/highcharts/tree/master/samples/highcharts/css/pattern/" rel="nofollow noreferrer">https://jsfiddle.net/gh/get/library/pure/highcharts/highcharts/tree/master/samples/highcharts/css/pattern/</a> - try exporting the chart.</p>
  <p>Anyone got any ideas? I think I could work around it by including the patternfill module and defining the patterns that way as well as in the CSS, but this feels like redundant code...</p>
  <p>Thanks,
  Rach</p>