Adding recursion unit test

ICD.Common.Utils.Tests/RecursionUtilsTest.cs

@@ -0,0 +1,40 @@
+using NUnit.Framework;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace ICD.Common.Utils.Tests
+{
+	[TestFixture]
+    public sealed class RecursionUtilsTest
+    {
+		[Test]
+		public void BreadthFirstSearchTest()
+		{
+			IEnumerable<int> GetChildren(int node)
+			{
+				switch (node)
+				{
+					case 1:
+						yield return 2;
+						yield return 3;
+						break;
+
+					case 2:
+						yield return 4;
+						break;
+
+					default:
+						yield break;
+				}
+			}
+
+			int[] nodes = RecursionUtils.BreadthFirstSearch(1, GetChildren).ToArray();
+
+			Assert.AreEqual(4, nodes.Length);
+			Assert.AreEqual(1, nodes[0]);
+			Assert.AreEqual(2, nodes[1]);
+			Assert.AreEqual(3, nodes[2]);
+			Assert.AreEqual(4, nodes[3]);
+		}
+	}
+}