Schedule a new event. The time argument should be a numeric type
compatible with the return value of the timefunc function passed
to the constructor. Events scheduled for
the same time will be executed in the order of their
Executing the event means executing
action(*argument). argument must be a
sequence holding the parameters for action.
Return value is an event which may be used for later cancellation of
the event (see cancel()).
Run all scheduled events. This function will wait
(using the delayfunc function passed to the constructor)
for the next event, then execute it and so on until there are no more
Either action or delayfunc can raise an exception. In
either case, the scheduler will maintain a consistent state and
propagate the exception. If an exception is raised by action,
the event will not be attempted in future calls to run().
If a sequence of events takes longer to run than the time available
before the next event, the scheduler will simply fall behind. No
events will be dropped; the calling code is responsible for canceling
events which are no longer pertinent.