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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 update_domain_queues(self):
        '''
        Check to update existing queues already in memory
        new queues are created elsewhere
        '''
        for key in self.domain_config:
            final_key = "{name}:{domain}:queue".format(
                    name=self.spider.name,
                    domain=key)
            # we already have a throttled queue for this domain, update it to new settings
            if final_key in self.queue_dict:
                self.queue_dict[final_key][0].window = float(self.domain_config[key]['window'])
                self.logger.debug("Updated queue {q} with new config"
                                  .format(q=final_key))
                # if scale is applied, scale back; otherwise use updated hits
                if 'scale' in self.domain_config[key]:
                    # round to int
                    hits = int(self.domain_config[key]['hits'] * self.fit_scale(
                               self.domain_config[key]['scale']))
                    self.queue_dict[final_key][0].limit = float(hits)
                else:
                    self.queue_dict[final_key][0].limit = float(self.domain_config[key]['hits'])