Implements an subclass of Session that knows about test users for a particular application. This should never be used from a real application, but may be useful for writing unit tests, etc.

Facebook allows developers to create test accounts for testing their applications' Facebook integration (see https://developers.facebook.com/docs/test_users/). This class simplifies use of these accounts for writing unit tests. It is not designed for use in production application code.

The main use case for this class is using TestSession.createSessionWithPrivateUser(android.app.Activity, java.util.List) or TestSession.createSessionWithSharedUser(android.app.Activity, java.util.List) to create a session for a test user. Two modes are supported. In "shared" mode, an attempt is made to find an existing test user that has the required permissions. If no such user is available, a new one is created with the required permissions. In "private" mode, designed for scenarios which require a new user in a known clean state, a new test user will always be created, and it will be automatically deleted when the TestSession is closed. The session obeys the same lifecycle as a regular Session, meaning it must be opened after creation before it can be used to make calls to the Facebook API.

Prior to creating a TestSession, two static methods must be called to initialize the application ID and application Secret to be used for managing test users. These methods are TestSession.setTestApplicationId(String) and TestSession.setTestApplicationSecret(String).

Note that the shared test user functionality depends on a naming convention for the test users. It is important that any testing of functionality which will mutate the permissions for a test user NOT use a shared test user, or this scheme will break down. If a shared test user seems to be in an invalid state, it can be deleted manually via the Web interface at https://developers.facebook.com/apps/APP_ID/permissions?role=test+users.