Replaced "retreive" with "retrieve".

src/Umbraco.Tests/Routing/NiceUrlProviderTests.cs

@@ -32,7 +32,7 @@ namespace Umbraco.Tests.Routing
         }
 
 		/// <summary>
-		/// This checks that when we retreive a NiceUrl for multiple items that there are no issues with cache overlap 
+		/// This checks that when we retrieve a NiceUrl for multiple items that there are no issues with cache overlap 
 		/// and that they are all cached correctly.
         /// </summary>
 		[Test]
@@ -182,4 +182,4 @@ namespace Umbraco.Tests.Routing
             Assert.AreEqual("#", routingContext.UrlProvider.GetUrl(999999));
 		}
 	}
-}
+}