Remove ObjectProperties from example

README.md

@@ -163,13 +163,14 @@ compiletime.
 If you want to make a function that manipulates an Activity, but not a normal object, you could
 bound the function like so:
 ```rust
-fn manipulator<T>(activity: T) -> Result<&mut ObjectProperties, SomeErrorType>
+fn manipulator<T>(activity: T) -> Result<(), SomeErrorType>
 where
     T: Activity + BaseExt,
 {
     activity
         .set_id("https://example.com".parse()?)
-        .set_context(context())
+        .set_context(context());
+    Ok(())
 }
 ```