An UIImageAsset extension with Dark Mode

UIImageAsset+TraitCollection.swift

import UIKit

public extension UIImageAsset {

    /// Creates an image asset with registration of tht eimages with the light and dark trait collections.
    /// - Parameters:
    ///   - lightModeImage: The image you want to register with the image asset with light user interface style.
    ///   - darkModeImage: The image you want to register with the image asset with dark user interface style.
    convenience init(lightModeImage: UIImage?, darkModeImage: UIImage?) {
        self.init()
        register(lightModeImage: lightModeImage, darkModeImage: darkModeImage)
    }

    /// Register an images with the light and dark trait collections respectively.
    /// - Parameters:
    ///   - lightModeImage: The image you want to register with the image asset with light user interface style.
    ///   - darkModeImage: The image you want to register with the image asset with dark user interface style.
    func register(lightModeImage: UIImage?, darkModeImage: UIImage?) {
        register(lightModeImage, for: .light)
        register(darkModeImage, for: .dark)
    }

    /// Register an image with the specified trait collection.
    /// - Parameters:
    ///   - image: The image you want to register with the image asset.
    ///   - traitCollection: The traits to associate with image.
    func register(_ image: UIImage?, for traitCollection: UITraitCollection) {
        guard let image = image else {
            return
        }
        register(image, with: traitCollection)
    }

    /// Returns the variant of the image that best matches the current trait collection. For early SDKs returns the image for light user interface style.
    func image() -> UIImage {
        if #available(iOS 13.0, tvOS 13.0, *) {
            image(with: .current)
        }
        return image(with: .light)
    }
}