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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def notch(self, frequency, type='iir', filtfilt=True, **kwargs):
 """Notch out a frequency in this `TimeSeries`. Parameters frequency : `float`, `~astropy.units.Quantity` frequency (default in Hertz) at which to apply the notch type : `str`, optional type of filter to apply, currently only 'iir' is supported **kwargs other keyword arguments to pass to `scipy.signal.iirdesign` Returns ------- notched : `TimeSeries` a notch-filtered copy of the input `TimeSeries` See Also -------- TimeSeries.filter for details on the filtering method scipy.signal.iirdesign for details on the IIR filter design method """

        zpk = filter_design.notch(frequency, self.sample_rate.value,
                                  type=type, **kwargs)
        return self.filter(*zpk, filtfilt=filtfilt)