code: def start(self, exceptions):
          
          if not self._interval:
              return False
          self._running.set()
          with self._lock:
              self._threshold = 0
              self._reads_since_check = 0
              self._writes_since_check = 0
          self._exceptions = exceptions
          LOGGER.debug('Heartbeat Checker Started')
          return self._start_new_timer()
docs: Start the Heartbeat Checker.
  
          :param list exceptions:
          :return: