title: C3.js: Assigning a chart height independently of the legend height
body: <p>(sorry for double posting, but the issue on github was not answered after one week: <a href="https://github.com/c3js/c3/issues/2254" rel="nofollow noreferrer">https://github.com/c3js/c3/issues/2254</a>)</p>
  
  <p>I'm using C3 JS and I have several stacked bar charts showing on the same page. Each one has a different legend, and some legends are quite bigger than others. Since I can only define the height for the whole image, the y-axis of charts with a bigger legend become smaller.</p>
  
  <p>The figure bellow illustrates the issue:</p>
  
  <p><a href="https://i.stack.imgur.com/LXBxW.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/LXBxW.png" alt="enter image description here"></a></p>
  
  <p>My target is that the y-axis have the same height on both charts. It does not matter the overall chart height (chart+legend).</p>
  
  <p>Is there any possibility of assigning a fixed height to the chart without including the legend height in this size? Maybe should I use D3 directly?</p>
  
  <p>Thanks for the attention and for this awesome library.</p>
  
  <p>best,
  alan</p>