Now returns the current absolute monotonic time.

Simulated implements a virtual Clock for reproducible time-sensitive tests.

SimulatedEvent implements Event for a virtual clock.

System implements Clock using the system clock.

Clock interface makes it possible to replace the monotonic system clock with a simulated clock.

Event represents a cancellable event returned by AfterFunc.

AbsTime represents absolute monotonic time.

SystemEvent implements Event using time.Timer.