title: nvd3 - how to disable tooltip in discrete bar chart
body: <p>I'm using nvd3 1.8.2, d3 3.5.8 and meteor 1.3.
  I used the <a href="http://nvd3.org/examples/discreteBar.html" rel="nofollow">example discreteBarChart from the nvd3 docs</a>.
  But when i try to disable the tooltips just like in the example with <code>chart.tooltips(false)</code> and i get a console error that says 'tooltip is not a function'.</p>
  
  <p>I also tried <code>chart.tooltip.enabled(false)</code>, that does not work either.</p>
  
  <p>See: </p>
  
  <pre><code>    // chart object
  let chart = nv.models.discreteBarChart()
      .x(function(d) {
          return d.x
      })
      .y(function(d) {
          return d.y
      })
      .staggerLabels(true)
      .showValues(false)
      .showYAxis(false)
      // .tooltips(false)
      .duration(250);
  
  // chart details
  nv.addGraph(function() {
      d3.select('#chartWordsAll svg')
        .datum(barChart())
        .call(chart);
  
      nv.utils.windowResize(chart.update);
  
      return chart;
  });
  </code></pre>
  
  <p>Any ideas how i can disable the tooltip?</p>
  
  <p>Thanks in advance!</p>
  
  <p>Muff</p>