title: Showing circle only for selected/highlighted value
body: <p>I was looking everywhere for this and wasn't able to find any solution or any hint on how to achieve this. I want to draw an indicator (circle) only for selected/highlighted point. Right now I have </p>
  
  <pre class="lang-swift prettyprint-override"><code>dataSet.drawCircleHoleEnabled = false
  dataSet.drawCirclesEnabled = false
  </code></pre>
  
  <p>So my line chart looks simple, but as soon as I start dragging my finder and seeing highlight indicator, I also want to see a circle showing me the data entry. 
  I want something which looks like this:</p>
  
  <p><a href="https://i.stack.imgur.com/S17h1.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/S17h1.png" alt="enter image description here"></a></p>
  
  <p>So far the only thing coming to my mind was creating another data set and configure it on the fly using delegates, but it seems like overkill for something so common.</p>