public void InvokeSimpleFunction()
{
ICommand body = new ReturnCommand(new VariableExpression("x"));
Function function = new Function(new string[] { "x" }, body);
Context context = new Context();
context.SetValue("x", 2);
object result = function.Invoke(context, null, new object[] { 1 });
Assert.IsNotNull(result);
Assert.AreEqual(1, result);
}