Package-level declarations

Why cached events were thrown away without being delivered.

Notified when the SDK discards cached events it will never deliver. Every discard is data the marketplace will not see, so a host that wants to know about loss - a metric, a crash-reporter breadcrumb - registers one via Analytics.eventDiscardListener.

Who the events reported after Analytics.setup belong to. Replaces a plain-String identity in which a blank silently meant "mint one for me" - a value that is easy to produce by accident and yields events that never audience-match.