def compliment_events(self, events, start, end):
"""
For a given set of datetime tuples of the form (start, end) which
falls in the range of the given start, end, what is the
complimentary set of events. That is, what are the other events,
togethor with the given events, which completely cover the given
start, end range?
"""
return AnalogSet.diffs([(start, end)], events)
