public void EatOperandAndReturnItKindTest()
        {
            // Arrange
            var snapshot = Mock.Of <ISnapshot>();
            var operand  = Mock.Of <IUnaryExpression>();
            var unaryOperatorExpression = Mock.Of <IUnaryOperatorExpression>(t => t.Operand == operand);
            var eater = Mock.Of <IEater>(t => t.Eat(snapshot, operand) == ExpressionKind.None);
            var unaryOperatorExpressionEater = new UnaryOperatorExpressionEater(eater);

            // Act
            var kind = unaryOperatorExpressionEater.Eat(snapshot, unaryOperatorExpression);

            // Assert
            Assert.AreEqual(kind, ExpressionKind.None);
        }
        public void EatOperandAndReturnItKindTest()
        {
            // Arrange
            var snapshot = Mock.Of<ISnapshot>();
            var operand = Mock.Of<IUnaryExpression>();
            var unaryOperatorExpression = Mock.Of<IUnaryOperatorExpression>(t => t.Operand == operand);
            var eater = Mock.Of<IEater>(t => t.Eat(snapshot, operand) == ExpressionKind.None);
            var unaryOperatorExpressionEater = new UnaryOperatorExpressionEater(eater);

            // Act
            var kind = unaryOperatorExpressionEater.Eat(snapshot, unaryOperatorExpression);

            // Assert
            Assert.AreEqual(kind, ExpressionKind.None);
        }