AppDelegate.swift

import UIKit

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {

    var window: UIWindow?
    
    // Instance variable to prevent deallocation.
    private let externalDependencies: ExternalDependeciesInjection = ExternalDependenciesImplementation()
    
    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
        
        // Set up SDKS
        externalDependencies.setup()
        return true
    }

    func applicationWillResignActive(_ application: UIApplication) {
        
        // Example of tracking an event.
        externalDependencies.track(event: "applicationWillResignActive")
    }

}