title: Adjust horizontal (preferred) size of an XYPlot in JFreeChart
body: <p>I have an <code>XYPlot</code> with an <code>XYBarRenderer</code>. This is used for a histogram. The horizontal spacing between the bins is too large, the bars are too wide. How can I decrease the 'preferred' bar width in this setting?</p>
  
  <p>Note that <code>setMaximumBarWidth</code> is not defined for <code>XYBarRenderer</code>.</p>