proxy.py

import time 

class SalesManager: 
 def work(self): 
 print("Sales Manager working...") 

 def talk(self): 
 print("Sales Manager ready to talk") 

class Proxy: 
 def __init__(self): 
 self.busy = 'No' 
 self.sales = None 

 def work (self): 
 print("Proxy checking for Sales Manager availability") 
 if self.busy == 'Yes': 
 self.sales = SalesManager() 
 time.sleep(2); 
 self.sales.talk() 
 else: 
 time.sleep(2); 
 print("Sales Manager is busy") 

if __name__ == '__main__':
 p = Proxy()
 p.work()
 p.busy = 'Yes'
 p.work()