     }
 }
 
+@available(macOS 10.13, iOS 11.0, tvOS 11.0, *)
 extension GPUContext {
     
     public func clip(rect: Rect) {

    }
}

extension GPUContext {
    
    public func draw(rect: Rect, color: CIColor) {

    }
}

@available(macOS 10.13, iOS 11.0, tvOS 11.0, *)
extension GPUContext {
    
    public func stroke(shape: Shape, width: Double, cap: Shape.LineCap, join: Shape.LineJoin, color: CIColor) {
