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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 psd(timeseries, method_func, *args, **kwargs):
 """Generate a PSD using a method function All arguments are presumed to be given in physical units Parameters timeseries : `~gwpy.timeseries.TimeSeries`, `tuple` the data to process, or a 2-tuple of series to correlate method_func : `callable` the function that will be called to perform the signal processing *args, **kwargs other arguments to pass to ``method_func`` when calling """

    # decorator has translated the arguments for us, so just call psdn()
    return _psdn(timeseries, method_func, *args, **kwargs)