Rename thread to _thread and dummy_thread to _dummy_thread. Issue #2875.
diff --git a/Demo/threads/Generator.py b/Demo/threads/Generator.py
index 0cc1bda..38c0c8a 100644
--- a/Demo/threads/Generator.py
+++ b/Demo/threads/Generator.py
@@ -1,6 +1,6 @@
 # Generator implementation using threads
 
-import thread
+import _thread as thread
 
 Killed = 'Generator.Killed'