title: Swift conversion: ERROR - CGPathAddArc
body: <p>I am attempting to convert my Swift 2 code into the latest syntax(Swift 3). I am receiving the following error:</p>
  
  <p><strong>Nil is not compatible with expected argument type 'UnsafePointer'</strong></p>
  
  <p><strong>(Swift 2 Code)<br>
  CGPathAddArc(path, nil, overlayView.frame.width - radius/2 - xOffset, yOffset, radius, 0.0, 2 * 3.14, false)</strong></p>
  
  <p>Can someone please help me resolve this conversion syntax issue? </p>