code: def add_value(self, val:float)->None:
          "Add `val` to calculate updated smoothed value."
          self.n += 1
          self.mov_avg = self.beta * self.mov_avg + (1 - self.beta) * val
          self.smooth = self.mov_avg / (1 - self.beta ** self.nf add_value(self, val:float)->None:
          "Add `val` to calculate updated smoothed value."
          self.n += 1
          self.mov_avg = self.beta * self.mov_avg + (1 - self.beta) * val
          self.smooth = self.mov_avg / (1 - self.beta ** self.n)
docs: Add `val` to calculate updated smoothed value.