add luxembourge test case

Author: selfmadecode

src/World.Net.UnitTests/Countries/LuxembourgTest.cs

@@ -0,0 +1,57 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace World.Net.UnitTests.Countries
+{
+    public class LuxembourgTest : AssertCountryTestBase
+    {
+        public static CountryIdentifier Id => CountryIdentifier.Luxembourg;
+        public string Name { get; } = "Luxembourg";
+        public string OfficialName { get; } = "Grand Duchy of Luxembourg";
+        public string NativeName { get; } = "Groussherzogtum Lëtzebuerg";
+        public string Capital { get; } = "Luxembourg City";
+        public int NumericCode { get; } = 442;
+        public string ISO2Code { get; } = "LU";
+        public string ISO3Code { get; } = "LUX";
+        public string[] CallingCode { get; } = ["+352"];
+        private static readonly (string Name, string IsoCode, string Type)[] States =
+        [
+            new("Capellen", "LU-CA", "Canton"),
+            new("Clervaux", "LU-CL", "Canton"),
+            new("Diekirch", "LU-DI", "Canton"),
+            new("Echternach", "LU-EC", "Canton"),
+            new("Esch-sur-Alzette", "LU-ES", "Canton"),
+            new("Grevenmacher", "LU-GR", "Canton"),
+            new("Luxembourg", "LU-LU", "Canton"),
+            new("Mersch", "LU-ME", "Canton"),
+            new("Redange", "LU-RD", "Canton"),
+            new("Remich", "LU-RM", "Canton"),
+            new("Vianden", "LU-VD", "Canton"),
+            new("Wiltz", "LU-WI", "Canton")
+        ];
+
+
+        [Fact]
+        public void GetCountry_ReturnsCorrectInformation_ForLuxembourg()
+        {
+            var country = CountryProvider.GetCountry(Id);
+
+            AssertCorrectInformation(
+                country,
+                Id,
+                Name,
+                OfficialName,
+                NativeName,
+                Capital,
+                NumericCode,
+                ISO2Code,
+                ISO3Code,
+                CallingCode,
+                States
+            );
+        }
+    }
+}