Verifies if an event is critical
(expired? current-time event)
Verifies if an event is expired
Get the most recent event from an event list
(most-recent? event1 event2)
Returns true if event 1 is most recent than event 2. Does not work with events with no time.
(tagged-all? tags event)
Predicate function to check if a collection of tags is present in the tags of event.
Verifies if an event is warning