class Program
{
    static void Main(string[] args)
    {
        using (var context = new MyContext())
        {
            var parentId = Guid.NewGuid();
            context.Parents.Add(new ParentEntity(null)
            {
                Id = parentId,
                Name = "Demo Parent",
                Children = new List<ChildEntity>
                {
                    new ChildEntity
                    {
                        Name = "First Child",
                        Id = Guid.NewGuid(),
                        ParentId = parentId
                    },
                    new ChildEntity
                    {
                        Name = "Second Child",
                        Id = Guid.NewGuid(),
                        ParentId = parentId
                    }
                }
            });
            context.SaveChanges();
        }

        using (var firstContext = new MyContext())
        {
            Console.WriteLine("Call without Include() will LazyLoad");
            var parent = firstContext.Parents.First();
            var firstChild = parent.Children.First();
            Console.WriteLine($"Child: {firstChild.Name}");
        }

        using (var secondContext = new MyContext())
        {
            Console.WriteLine("Call with Include()");
            var parent = secondContext.Parents.Include(x => x.Children).First();
            var secondChild = parent.Children.Last();
            Console.WriteLine($"Child: {secondChild.Name}");
        }

        Console.ReadKey();
    }
}