public void EdmLabeledExpression()
        {
            var e = new EdmLabeledExpression("l1", new EdmStringConstant("qwerty"));

            Assert.AreEqual("l1", e.Name, "e.Label");
            Assert.AreEqual("qwerty", ((IEdmStringValue)e.Expression).Value, ((IEdmStringValue)e.Expression).Value);
            Assert.IsFalse(e.IsBad(), "e good");

            try
            {
                new EdmLabeledExpression(null, new EdmStringConstant("qwerty"));
                Assert.Fail("exception expected.");
            }
            catch (ArgumentNullException)
            {
            }

            try
            {
                new EdmLabeledExpression("l1", null);
                Assert.Fail("exception expected.");
            }
            catch (ArgumentNullException)
            {
            }

            var ee = new MutableLabeledExpression();

            Assert.IsNull(ee.Name, "ee.Label");
            Assert.IsNull(ee.Expression, "ee.Expression");
            Assert.IsTrue(ee.IsBad(), "Expression is bad.");
            Assert.AreEqual(2, ee.Errors().Count(), "Expression has errors");
        }
        public void EdmLabeledExpression()
        {
            var e = new EdmLabeledExpression("l1", new EdmStringConstant("qwerty"));
            Assert.AreEqual("l1", e.Name, "e.Label");
            Assert.AreEqual("qwerty", ((IEdmStringValue)e.Expression).Value, ((IEdmStringValue)e.Expression).Value);
            Assert.IsFalse(e.IsBad(), "e good");

            try
            {
                new EdmLabeledExpression(null, new EdmStringConstant("qwerty"));
                Assert.Fail("exception expected.");
            }
            catch (ArgumentNullException)
            {
            }

            try
            {
                new EdmLabeledExpression("l1", null);
                Assert.Fail("exception expected.");
            }
            catch (ArgumentNullException)
            {
            }

            var ee = new MutableLabeledExpression();
            Assert.IsNull(ee.Name, "ee.Label");
            Assert.IsNull(ee.Expression, "ee.Expression");
            Assert.IsTrue(ee.IsBad(), "Expression is bad.");
            Assert.AreEqual(2, ee.Errors().Count(), "Expression has errors");
        }