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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 _growth_curve_single_site(self, distr='glo'):
 """ Return flood growth curve function based on `amax_records` from the subject catchment only. :return: Inverse cumulative distribution function with one parameter `aep` (annual exceedance probability) :type: :class:`.GrowthCurve` """

        if self.catchment.amax_records:
            self.donor_catchments = []
            return GrowthCurve(distr, *self._var_and_skew(self.catchment))
        else:
            raise InsufficientDataError("Catchment's `amax_records` must be set for a single site analysis.")