code: def taper_shift(waveform, output):
      
  
      if len(waveform) == len(output):
          output.data += waveform.data
      else:
          output.data[len(output)-len(waveform):] += waveform.data
  
      return output
docs: Add waveform to output with waveform shifted accordingly (for tapering
      multi-mode ringdowns)