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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 glover_hrf(tr, oversampling=50, time_length=32., onset=0.):
 """ Implementation of the Glover hrf model Parameters tr : float scan repeat time, in seconds oversampling : int, optional temporal oversampling factor time_length : float, optional hrf kernel length, in seconds onset : float, optional onset of the response Returns ------- hrf: array of shape(length / tr * oversampling, dtype=float) hrf sampling on the oversampled time grid """

    return _gamma_difference_hrf(tr, oversampling, time_length, onset,
                                delay=6, undershoot=12., dispersion=.9,
                                u_dispersion=.9, ratio=.35)