title: How to change legend icon in pie chart, i am using charts_flutter 0.9.0
body: <p>I am trying to change the legend icon from circle to rectangle for my pie chart. I am using the below lines for that but am getting error right away. </p>
  
  <pre><code>defaultRenderer: new charts.ArcRendererConfig(
            symbolRenderer: new IconRenderer(Icons.cloud)
        ),
  </code></pre>
  
  <p>I am getting the error (screenshot attached) 
  <a href="https://i.stack.imgur.com/cRaDy.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/cRaDy.png" alt=""></a>
  please help me to change the default icon for the legend in pie chart.</p>