title: How to rotated left axis label in stack bar charts?
body: <p>I am using Charts library. I want to rotate left axis label to 90 degrees. How can I do that? Please help me.</p>
  
  <p>I am able to rotate <code>xAxis</code> label. This is how I rotate <code>xAxis</code>:</p>
  
  <pre><code>barChart.xAxis.labelPosition = XAxis.LabelPosition.topInside
  barChart.xAxis.labelRotationAngle = kXAxisLabelRotationAngleForShareOfVoiceByDrugs
  </code></pre>
  
  <p>And for <code>leftAxis</code>:</p>
  
  <pre><code>barChart.leftAxis.valueFormatter = IndexAxisValueFormatter(values:hotTopicsAndWeakSignalsModel.barChartDrugNames)
  barChart.leftAxis.labelPosition = .outsideChartr
  </code></pre>
  
  <p>How can set rotation to <code>leftAxis</code>?</p>