BillingClientStateListener (Appstore Billing Compatibility 4.0.0 API)

```
public interface BillingClientStateListener
```
Callback for setup process.
This listener's onBillingSetupFinished(BillingResult) method is called when the setup process is complete.

All Methods Instance Methods Abstract Methods
Modifier and Type	Method and Description
`void`	`onBillingServiceDisconnected()` Called to notify that the connection to the billing service was lost.
`void`	`onBillingSetupFinished(BillingResult billingResult)` Called to notify that setup is complete.

Interface BillingClientStateListener