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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 InitializeMonitorThread(self):
 """Start the thread that registers the size of the DataStore."""

    if self.monitor_thread:
      return
    self.monitor_thread = utils.InterruptableThread(
        name="DataStore monitoring thread",
        target=self._RegisterSize,
        sleep_time=60)
    self.monitor_thread.start()