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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 get_stdev(self, asset_type):
 """ Returns the standard deviation for a set of a certain asset type. :param asset_type: ``str`` of the asset type to calculate standard deviation for. :returns: A ``int`` or ``float`` of standard deviation, depending on the self.decimal_precision """

        load_times = []
        # Handle edge cases like TTFB
        if asset_type == 'ttfb':
            for page in self.pages:
                if page.time_to_first_byte is not None:
                    load_times.append(page.time_to_first_byte)
        elif asset_type not in self.asset_types and asset_type != 'page':
            raise ValueError('asset_type must be one of:\nttfb\n{0}'.format(
                    '\n'.join(self.asset_types)))
        else:
            load_times = self.get_load_times(asset_type)

        if not load_times or not sum(load_times):
            return 0
        return round(stdev(load_times),
                     self.decimal_precision)