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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 rayleigh_spectrum(self, fftlength=None, overlap=None):
 """Calculate the Rayleigh `FrequencySeries` for this `TimeSeries`. The Rayleigh statistic is calculated as the ratio of the standard deviation and the mean of a number of periodograms. Parameters fftlength : `float` number of seconds in single FFT, defaults to a single FFT covering the full duration overlap : `float`, optional number of seconds of overlap between FFTs, defaults to that of the relevant method. Returns ------- psd : `~gwpy.frequencyseries.FrequencySeries` a data series containing the PSD. """

        return spectral.psd(
            self,
            spectral.rayleigh,
            fftlength=fftlength,
            overlap=overlap,
        )