   
   // MARK: - Parallelogram
   
-  private func maskParallelogram(_ topLeftAngle: Double = 60) {
+  private func maskParallelogram(_ topLeftAngle: Double) {
     let parallelogramPath = maskParallelogramBezierPath(topLeftAngle)
     drawPath(parallelogramPath)
   }

  
  // MARK: - Polygon
  
  private func maskPolygon(_ sides: Int = 6) {
    let polygonPath = maskPolygonBezierPath(max(sides, 3))
    drawPath(polygonPath)
  }

  // MARK: - Star
  
  // See https://www.weheartswift.com/bezier-paths-gesture-recognizers/
  private func maskStar(_ points: Int) {
    // FIXME: Do not mask the shadow.
    
    // Stars must has at least 3 points.
