title: D3JS remove classes similar to JQuery removeClass()?
body: <p>Is there a D3JS equivalent to Jquery's <code>removeClass()</code> ?</p>
  
  <p>I want to remove all classes from a circle shape. I currently explicitly name and remove each class:</p>
  
  <pre><code>.on("click", function() {
    d3.select("#circle" + i)
      .classed("foo", false)
      .classed("bar", false) 
    }
  </code></pre>
  
  <p>I could test for foo, bar, and remove only when present, but I want to anticipate as-yet unnamed classes for removal and make my code more efficient.</p>