Android in app re-subscription testing

I'm sorry, my wrong english but please help me T.T

I am testing the in app subscription on android devices(In app billing V3. api). I have some problems about re-subscription.

I refers to documents about re-subscription.

To help users who cancel a subscription and want to subscribe again, you can add the ability for users to resubscribe without having to wait until the end of their existing subscription period. When a user resubscribes before the end of their existing subscription period, they'll see a $0.00 charge.

http://ift.tt/1Q5d42I

But document of link is just explain manual renewal.

Manual Renewal

With version 3 of the In-app Billing API, users can renew a subscription during its active period even if the subscription is not set to automatically renew. If the user purchases a subscription while the subscription is active, it is extended by the appropriate period at the current rate.

For example, Achilles has a subscription to the Modern Hoplite app. His subscription is currently due to expire on August 1. On July 10, he purchases a 1-month subscription at the current rate. This one month is added to his existing subscription, so the subscription now expires on September 1.

It is up to the app to convey this with an appropriate UI. For example, if a user does not have an active subscription, the app might have a buy button, but if the user has a subscription the button might say renew.

http://ift.tt/1O8G0lD

Actually I try to re-subscription test with test account, paid full charge and success re-subscription. but I can't check by receipt. autoRenewing flag of receipt is false.