code: def update_with_increment_value(self, increment_value, mesg=None):
          
          self.cur_value += increment_value
          self.update(self.cur_value, mesg)
docs: Update progressbar with the value of the increment instead of the
          current value of process as in update()
  
          Parameters
          ----------
          increment_value : int
              Value of the increment of process.  The percent of the progressbar
              will be computed as
              (self.cur_value + increment_value / max_value) * 100
          mesg : str
              Message to display to the right of the progressbar.  If None, the
              last message provided will be used.  To clear the current message,
              pass a null string, ''.