public override void OnNavigatingTo(NavigationParameters parameters)
        {
            base.OnNavigatingTo(parameters);

            if (parameters.TryGetParam <string>(MainPage.AnotherParameter, out var paramString))
            {
                Title = paramString;
            }

            if (!Contacts.Any())
            {
                var contacts = _contactService.GetContacts();
                foreach (var contact in contacts)
                {
                    //TODO: opportunity to use enhanced observable collection from MVVM Helpers package?
                    Contacts.Add(contact);
                }
            }
        }