Step $3$: Implement TimeoutManager's add$\_$timeout$()$ and update$()$ methods

Complete the TimeoutManager class implementation in TimeoutManager.py$.$ add$\_$timeout$()$ must add a new Timeoutltem to the priority queue that expires delay$\_$before$\_$callback milliseconds after the current time. update$()$ must dequeue and call the callback function for each expired timeout item. Use TimeoutManager's clock attributes to get the current time.

Step $4$: Test in develop mode, then submit

File main.py contains two automated tests that can be run in develop mode. Each adds timeouts and invokes updates at various times, then verifies that the proper callback functions are called during each update. Additional tests can be added, if desired. Ensure that the two tests in develop mode pass before submitting your code.

Downloadable files

Current file: TimeoutManager.py

$```$

import sys

from queue import PriorityQueue

from TimeoutItem import TimeoutItem

from Clocks import $*$

Class TimeoutManager:

def $\_\_$init$\_\_($self$,$ clock$)$:

# The current time used by the add$\_$timeout$()$ and update$()$

self.clock $=$ clock

# A priority queue of TimeoutItems. The timeout item with the

# Lowest callback time is the first to be dequeued.

self.pq $=$ PriorityQueue$()$

# Return a timeout manager's internal priority queue.

# Used only for grading purposes.

def get$\_$priority$\_$queue$($self$)$:

return self.pq

def get$\_$priority$\_$queue$\_$times$($self$)$:

return sorted$([$entry$.$get$\_$callback$\_$time$()$ for entry in self.pq$.$queue$])$

# Add a TimeoutItem.

# The added timeout expires at:

# $($clock$\text{'}$s current time when self function is called$)+($item$\text{'}$s delay time$)$

def add$\_$timeout$($self$,$

delay$\_$before$\_$callback,

callback$)$:

# Type your code here.

pass

# Dequeues each expired TimeoutItem from the priority queue in order of their

# priority and calls each expired item's callback function.

def update$($self$)$:

# Type your code here.

pass

$```$