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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 flat_unity(length, delta_f, low_freq_cutoff):
 """ Returns a FrequencySeries of ones above the low_frequency_cutoff. Parameters length : int Length of output Frequencyseries. delta_f : float Frequency step for output FrequencySeries. low_freq_cutoff : int Low-frequency cutoff for output FrequencySeries. Returns ------- FrequencySeries Returns a FrequencySeries containing the unity PSD model. """

    fseries = FrequencySeries(numpy.ones(length), delta_f=delta_f)
    kmin = int(low_freq_cutoff / fseries.delta_f)
    fseries.data[:kmin] = 0
    return fseries