transaction context manager added

--HG--
branch : sandbox

src/zodb/tutorial.py

@@ -14,6 +14,7 @@ from __future__ import unicode_literals
 
 from ZODB.FileStorage import FileStorage
 from ZODB.DB import DB
+from ZEO.ClientStorage import ClientStorage
 from persistent import Persistent
 import transaction
 
@@ -33,7 +34,8 @@ class Account(Persistent):
 
 # Configuration
 
-storage = FileStorage(r"e:\workspaces\zodb3\tutorial.zodb")
+# storage = FileStorage(r"e:\workspaces\zodb3\tutorial.zodb")
+storage = ClientStorage(8090)
 db = DB(storage)
 ctx = db.open()
 root = ctx.root()
@@ -62,6 +64,7 @@ print(root.keys())
 # ['account-1', 'account-2']
 
 print(root['account-2'].balance)
-a = root['account-1']
-b = root['account-2']
+with transaction.manager:
+    a = root['account-1']
+    b = root['account-2']
 print("id(a): {}, id(b): {}".format(id(a), id(b)))