code: def fd_to_td(htilde, delta_t=None, left_window=None, right_window=None,
            left_beta=8, right_beta=8):
      
      if left_window is not None:
          start, end = left_window
          htilde = fd_taper(htilde, start, end, side='left', beta=left_beta)
      if right_window is not None:
          start, end = right_window
          htilde = fd_taper(htilde, start, end, side='right', beta=right_beta)
      return htilde.to_timeseries(delta_t=delta_t)
docs: Converts a FD waveform to TD.
  
      A window can optionally be applied using ``fd_taper`` to the left or right
      side of the waveform before being converted to the time domain.
  
      Parameters
      ----------
      htilde : FrequencySeries
          The waveform to convert.
      delta_t : float, optional
          Make the returned time series have the given ``delta_t``.
      left_window : tuple of float, optional
          A tuple giving the start and end frequency of the FD taper to apply
          on the left side. If None, no taper will be applied on the left.
      right_window : tuple of float, optional
          A tuple giving the start and end frequency of the FD taper to apply
          on the right side. If None, no taper will be applied on the right.
      left_beta : int, optional
          The beta parameter to use for the left taper. See ``fd_taper`` for
          details. Default is 8.
      right_beta : int, optional
          The beta parameter to use for the right taper. Default is 8.
  
      Returns
      -------
      TimeSeries
          The time-series representation of ``htilde``.