code: def start(self, max_val):
      
      self._timer.init_timer(max_value=max_val)
  
      self._infinite_mode = max_val <= 0
      self._infinite_position = 0
  
      self._max = max_val
      self._fill_empty()
      self._value = 0
      self.progress(0)
      self._status = ProgressBarStatus.started
docs: :arg max_val Maximum value
      :type max_val int