title: Zoomable Sunburst with Labels issue
body: <p>I am using metmajer’s <a href="http://bl.ocks.org/metmajer/5480307" rel="nofollow noreferrer">Zoomable Sunburst with Labels</a>:</p>
  
  <p><img src="https://i.stack.imgur.com/0xgcK.png" alt="enter image description here"></p>
  
  <p>...with large number of nodes. It appears that the labels are very unclear for small partitions and the chart zooms too slow. Is there any way I can hide the labels if not clear (may be depending on depth) so that my chart is clear and fast as well?</p>