calayer:
An object that manages image-based content and allows you to perform animations on that content.
- (nullable instancetype)presentationLayer;
- (instancetype)modelLayer;
@property(nullable, strong) __kindof CALayer *mask;
@property BOOL masksToBounds;
/* Reload the content of this layer. Calls the -drawInContext: method
* then updates the `contents' property of the layer. Typically this is
* not called directly. */
- (void)display;
@property BOOL drawsAsynchronously
@property BOOL allowsEdgeAntialiasing
API_AVAILABLE(macos(10.10), ios(2.0), watchos(2.0), tvos(9.0));
@property BOOL allowsGroupOpacity
/* When true, the layer is rendered as a bitmap in its local coordinate
* space ("rasterized"), then the bitmap is composited into the
* destination
@property BOOL shouldRasterize;