code: def clip(self, lower=0, upper=127):
          
          self.pianoroll = self.pianoroll.clip(lower, upper)
docs: Clip the pianoroll by the given lower and upper bounds.
  
          Parameters
          ----------
          lower : int or float
              The lower bound to clip the pianoroll. Defaults to 0.
          upper : int or float
              The upper bound to clip the pianoroll. Defaults to 127.