code: def clip(obj, lower=0, upper=127):
      
      _check_supported(obj)
      copied = deepcopy(obj)
      copied.clip(lower, upper)
      return copied
docs: Return a copy of the object with piano-roll(s) clipped by a lower bound
      and an upper bound specified by `lower` and `upper`, respectively.
  
      Parameters
      ----------
      lower : int or float
          The lower bound to clip the piano-roll. Default to 0.
      upper : int or float
          The upper bound to clip the piano-roll. Default to 127.