The Event mechanism, introduced in JDK-8242060, serves as a hidden communication channel that enables certain lower-level methods invoked by the `jarsigner` tool to report events back to it. This mechanism operates globally, allowing only one reporter to be registered for each event type at any given time. As a result, if multiple `jarsigner` instances run simultaneously (for example, when `s.s.t.jarsigner.Main#main` is called directly), events may be reported to the incorrect instance.