title: adding html to google chart tooltip
body: <p>I'm using google chart api.</p>
  
  <p>javascript code :</p>
  
  <pre><code>       var data = new google.visualization.DataTable();
         data.addColumn('number', 'buy'); 
         data.addColumn('number', 'sell'); 
         data.addColumn({type:'string', role:'tooltip'});
         data.addRows( ... my data here  ... 
                     [[ 10 ,12 , "I'm very long long message in tooltip" ] [ ...  and more data.
  </code></pre>
  
  <p>the tooltip on the chart shows "I'm very long long message in tooltip" in 1 line. </p>
  
  <p>how can I make the tooltip be 50px width ... or have inside <br/> ?</p>