         }
         
         if let delegate = self.delegate {
-            delegate.startedDrawing!()
+            delegate.startedDrawing()
         }
     }
     

    }
}

// MARK: - Optional Protocol Methods for YPDrawSignatureViewDelegate
/// ## YPDrawSignatureViewDelegate Protocol
/// YPDrawSignatureViewDelegate:
/// - startedDrawing()
/// - finishedDrawing()
@objc protocol YPSignatureDelegate: class {
    @objc optional func startedDrawing()
    @objc optional func finishedDrawing()
}

@IBDesignable
public class YPDrawSignatureView: UIView {
    
    weak var delegate: YPSignatureDelegate?
    
    // MARK: - Public properties
    @IBInspectable public var strokeWidth: CGFloat = 2.0 {
