public void ParsePrimitive()
{
ModelParser parser = new ModelParser("<primitive: 60>");
IExpression expression = parser.ParseExpression();
Assert.IsNotNull(expression);
Assert.IsInstanceOfType(expression, typeof(PrimitiveExpression));
PrimitiveExpression pexpression = (PrimitiveExpression)expression;
Assert.AreEqual(60, pexpression.Number);
Assert.AreEqual("<primitive: 60>", expression.AsString());
}