registerExtension()API registers the Identity extension with the Mobile Core extension. This API allows the extension to send and receive events to and from the Mobile SDK.
setApplication()method in the
onCreate()method, register the extension. If the registration was not successful, an
extensionVersion()API returns the version of the Identity extension that is registered with the Mobile Core extension.
midparameter exists on each hit, and that this value matches the
midvalue that is being sent by the app code.