code: def fir_zero_filter(self, coeff):
          
          from pycbc.filter import fir_zero_filter
          return self._return(fir_zero_filter(coeff, self))
docs: Filter the timeseries with a set of FIR coefficients
  
          Parameters
          ----------
          coeff: numpy.ndarray
              FIR coefficients. Should be and odd length and symmetric.
  
          Returns
          -------
          filtered_series: pycbc.types.TimeSeries
              Return the filtered timeseries, which has been properly shifted to account
          for the FIR filter delay and the corrupted regions zeroed out.