Move importlib completely over to using rpartition and accepting the empty
string for top-level modules.
diff --git a/Lib/importlib/NOTES b/Lib/importlib/NOTES
index 05920ad..f0d8e43 100644
--- a/Lib/importlib/NOTES
+++ b/Lib/importlib/NOTES
@@ -1,10 +1,7 @@
 to do
 /////
 
-* Use rpartition for getting the package of a module.
-
-    + Make sure there is a test for the empty string as acceptable for
-      __package__.
+* Extract test_path_hooks constants into a util module for extension testing.
 
 * Implement PEP 302 protocol for loaders (should just be a matter of testing).