title: Change size of legend symbol
body: <p>How do I change the size of the symbols in the legend? Right now they look like this:</p>
  
  <p><a href="https://i.stack.imgur.com/3ixRj.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/3ixRj.png" alt="enter image description here"></a></p>
  
  <p>I would like them to be squares approximately the same size as the titles. After looking at the docs, I thought changing symbolHeight, symbolRadius and symbolWidth would do the trick, but it doesn't. In fact these parameters don't change anything at all, as far as I can see. </p>