function is allowed to modify the queue. Time can be expressed as
integers or floating point numbers, as long as it is consistent.
-Events are specified by tuples (time, priority, action, argument).
+Events are specified by tuples (time, priority, action, argument).
As in UNIX, lower priority numbers mean higher priority; in this
way the queue can be maintained as a priority queue. Execution of the
event means calling the action function, passing it the argument
sequence in "argument" (remember that in Python, multiple function
-arguments are be packed in a sequence).
+arguments are be packed in a sequence).
The action function may be an instance method so it
has another way to reference private data (besides global variables).
"""An ordered list of upcoming events.
Events are named tuples with fields for:
- time, priority, action, arguments
+ time, priority, action, arguments
# Use heapq to sort the queue rather than using 'sorted(self._queue)'.