public void ShouldGetCorrectNullConstant()
        {
            var constExpr = new MdxConstantExpression().WithValue(null);
            var expr      = constExpr.ToString();

            expr.Should().Be(MdxConstants.NullConstant);
        }
        public void ShouldGetCorrectIntConstant(int value, string expectedExpr)
        {
            var constExpr = new MdxConstantExpression().WithValue(value);
            var expr      = constExpr.ToString();

            expr.Should().Be(expectedExpr);
        }