Tutorial: Clarify Step 4 TODO 4

Help/guide/tutorial/Adding Generator Expressions.rst

@@ -149,8 +149,8 @@ interface library.
 
 Lastly, we only want these warning flags to be used during builds. Consumers
 of our installed project should not inherit our warning flags. To specify
-this, we wrap our flags in a generator expression using the ``BUILD_INTERFACE``
-condition. The resulting full code looks like the following:
+this, we wrap our flags from TODO 3 in a generator expression using the
+``BUILD_INTERFACE`` condition. The resulting full code looks like the following:
 
 .. raw:: html