public void be_in_game_when_have_gift()
        {
            var elf = new Elf();

            Assert.True(elf.HasGift);
            Assert.True(elf.IsInGame());
        }
        public void leave_the_game_when_no_gifts()
        {
            var elf = new Elf();

            elf.RemoveFromGame();
            Assert.False(elf.IsInGame());
        }