Added TryUpdate_ShouldReturnFalse_WhenKeyMissing

Author: zbalkan

TechnitiumLibrary.UnitTests/TechnitiumLibrary.ByteTree/ByteTreeTests.cs

@@ -202,6 +202,14 @@ public void TryUpdate_ShouldThrow_WhenNullKey()
             Assert.ThrowsExactly<ArgumentNullException>(() => tree.TryUpdate(null, "x", "y"));
         }
 
+        [TestMethod]
+        public void TryUpdate_ShouldReturnFalse_WhenKeyMissing()
+        {
+            ByteTree<string> tree = new ByteTree<string>();
+            Assert.IsFalse(tree.TryUpdate(Key(9), "x", "y"));
+        }
+
+
         // ---------------------------
         // AddOrUpdate
         // ---------------------------