old_contents: #
  # stopwatch.py <Peter.Bienstman@UGent.be>
  #
  
  import time
  
  
  class Stopwatch(object):
  
      def __init__(self):
          self.start_time = 0
          self.running_time = 0
  
      def start(self):
          self.start_time = time.time()
          self.running_time = 0
  
      def pause(self):
          self.running_time += time.time() - self.start_time
  
      def unpause(self):
          self.start_time = time.time()
  
      def stop(self):
          self.running_time += time.time() - self.start_time
          self.start_time = 0
          return self.running_time
          
      def time(self):
          return self.running_time
  
  
new_contents: #
  # stopwatch.py <Peter.Bienstman@UGent.be>
  #
  
  import time
  
  
  class Stopwatch(object):
  
      def __init__(self):
          self.start_time = 0
          self.running_time = 0
  
      def start(self):
          self.start_time = time.time()
          self.running_time = 0
  
      def pause(self):
          self.running_time += time.time() - self.start_time
  
      def unpause(self):
          self.start_time = time.time()
  
      def stop(self):
          self.running_time += time.time() - self.start_time
          self.start_time = 0
          return self.running_time
          
      def time(self):
          return self.running_time
  
  
  stopwatch = Stopwatch()
  
  
subject: Revert stopwatch change (breaks existing code).