public void ParseUnaryMessage()
{
ModelParser parser = new ModelParser("x length");
IExpression expression = parser.ParseExpression();
Assert.IsNotNull(expression);
Assert.IsInstanceOfType(expression, typeof(MessageExpression));
MessageExpression mexpression = (MessageExpression)expression;
Assert.IsInstanceOfType(mexpression.Target, typeof(VariableExpression));
Assert.AreEqual("length", mexpression.Selector);
Assert.AreEqual(0, mexpression.Arguments.Count());
Assert.AreEqual("x length", expression.AsString());
}