Rename thread to _thread and dummy_thread to _dummy_thread. Issue #2875.
diff --git a/Demo/metaclasses/Synch.py b/Demo/metaclasses/Synch.py
index 445ce83..e02f88f 100644
--- a/Demo/metaclasses/Synch.py
+++ b/Demo/metaclasses/Synch.py
@@ -4,7 +4,7 @@
 
 """
 
-import thread
+import _thread as thread
 
 # First we need to define a reentrant lock.
 # This is generally useful and should probably be in a standard Python