SwiftTip20.swift

// This API is available in iOS 16, macOS 13.0, tvOS 16.0, watchOS 9.0.
// Using backDeployed we can make it available in old OSes, like iOS 15 etc
extension Font {
  @backDeployed(before: iOS 16.0, macOS 13.0, tvOS 16.0, watchOS 9.0)
  @available(iOS 15.0, macOS 12.0, tvOS 15.0, watchOS 8.0, *)
  public static func system(size: CGFloat, weight: Font.Weight? = nil, design: Font.Design? = nil) -> Font {
    fatalError("Implement")
  }
}