public void NegationString()
        {
            NegationExpression expr = new NegationExpression(new ConstantExpression("foo"));

            Assert.AreEqual(false, expr.Evaluate(null));
        }
        public void NegationInteger()
        {
            NegationExpression expr = new NegationExpression(new ConstantExpression(123));

            Assert.AreEqual(false, expr.Evaluate(null));
        }
        public void NegationTrue()
        {
            NegationExpression expr = new NegationExpression(new ConstantExpression(true));

            Assert.AreEqual(false, expr.Evaluate(null));
        }