code: def pad_to_multiple(obj, factor):
      
      _check_supported(obj)
      copied = deepcopy(obj)
      copied.pad_to_multiple(factor)
      return copied
docs: Return a copy of the object with its piano-roll padded with zeros at the
      end along the time axis with the minimal length that make the length of
      the resulting piano-roll a multiple of `factor`.
  
      Parameters
      ----------
      factor : int
          The value which the length of the resulting piano-roll will be
          a multiple of.