public void Happypath()
        {
            var popCenter = new SiteDefinition()
            {
                Name        = "Population Center",
                Description = "A center of population.",
            };

            popCenter.Attributes["Evil"] = new AttributeDefinition()
            {
                BaseValue = "Rand.Next(-5, 5)"
            };
            popCenter.Attributes["Population"] = new AttributeDefinition()
            {
                BaseValue = "Rand.Next(0, 1000000)"
            };

            var cityDef = new SiteDefinition()
            {
                Name         = "City",
                Description  = "A moderate sized settlement",
                InheritsFrom = "Population Center",
            };

            cityDef.Attributes["Population"] = new AttributeDefinition()
            {
                BaseValue = "Rand.Next(20000, 100000)"
            };

            IList <SiteDefinition> sites = new List <SiteDefinition>
            {
                popCenter,
                cityDef,
            };

            var definitions = new Definitions(sites);

            int    worldSeed = 915434125;
            Random rdm       = new Random(worldSeed);

            ConditionCompiler <BaseGlobalVariables> processor = new ConditionCompiler <BaseGlobalVariables>(new BaseGlobalVariables()
            {
                World = new Contracts.World(),
            });

            definitions.Attach(processor);
            ThingFactory factory = new ThingFactory(definitions);

            for (int i = 0; i < 100; i++)
            {
                Site city = factory.CreateSite(rdm, 0, 0, "City");
                city.FinalizeConstruction(rdm);
                Console.WriteLine($"City created: {city.EffectiveAttribute("Population")} {city.EffectiveAttribute("Evil")}");

                Assert.AreEqual(ThingType.Site, city.ThingType);
                Assert.AreEqual(cityDef, city.Definition);
                int population = city.EffectiveAttribute("Population");
                Assert.IsTrue(population <= 100000);
                Assert.IsTrue(population >= 20000);
                int evil = city.EffectiveAttribute("Evil");
                Assert.IsTrue(evil <= 5);
                Assert.IsTrue(evil >= -5);
            }
        }