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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def stop(self, timeout_s=None):
 """Stops the interval. If a timeout is provided and stop returns False then the thread is effectively abandoned in whatever state it was in (presumably dead-locked). Args: timeout_s: The time in seconds to wait on the thread to finish. By default it's forever. Returns: False if a timeout was provided and we timed out. """

    self.stopped.set()
    if self.thread:
      self.thread.join(timeout_s)
      return not self.thread.isAlive()
    else:
      return True