old_contents: from threading import Thread, Event
  
  class SyncThread(Thread):
  
  	def __init__(self, parent):
  		Thread.__init__(self)
  		self.parent = parent
  		self.event = Event()
  		self.elapsed = 0
  		self.interval = 300
  
  	def run(self):
  		while not self.event.is_set():
  			if self.elapsed < self.interval:
  				self.elapsed += 1
  				self.event.wait(1)
  			else:
  				self.elapsed = 0
  
  				print "Starting periodic synchornization."
  				parent.tracker.sync()
  
  	def stop(self):
  		self.event.set()
new_contents: from threading import Thread, Event
  
  class SyncThread(Thread):
  
  	def __init__(self, parent):
  		Thread.__init__(self)
  		self.parent = parent
  		self.event = Event()
  		self.elapsed = 0
  		self.interval = 300
  
  	def run(self):
  		while not self.event.is_set():
  			if self.elapsed < self.interval:
  				self.elapsed += 1
  				self.event.wait(1)
  			else:
  				self.elapsed = 0
  
  				print "Starting periodic synchronization."
  				self.parent.tracker.sync()
  
  	def stop(self):
  		self.event.set()
  
subject: Fix mispelling in worker script