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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 load(self, filename):
 """Load proxies from file"""

        with open(filename, 'r') as fin:
            proxies = json.load(fin)
        for protocol in proxies:
            for proxy in proxies[protocol]:
                self.proxies[protocol][proxy['addr']] = Proxy(
                    proxy['addr'], proxy['protocol'], proxy['weight'],
                    proxy['last_checked'])
                self.addr_list[protocol].append(proxy['addr'])