Add emulation of transaction retries to memory impl of RunInTransaction.

service/taskqueue/interface.go

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 package taskqueue
 
 // Interface is the full interface to the Task Queue service.
 type Interface interface {
         // NewTask simply creates a new Task object with the Path field populated.
         // The path parameter may be blank, if you want to use the default task path
@@ skipping 22 matching lines @@
         // processing multiple work items at a time.
         //
         // Lease would also take care of calling ModifyLease as necessary to ensure
         // that each call to cb would have 'duration' amount of time to work on the
         // task, as well as releasing as many leased tasks as it can on a failure.
 
         Purge(queueName string) error
 
         Stats(queueNames ...string) ([]Statistics, error)
 
+        Testable() Testable
+
         Raw() RawInterface
 }