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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 list_pubs(self, buf):
 """SSH v2 public keys are serialized and returned."""

        assert not buf.read()
        keys = self.conn.parse_public_keys()
        code = util.pack('B', msg_code('SSH2_AGENT_IDENTITIES_ANSWER'))
        num = util.pack('L', len(keys))
        log.debug('available keys: %s', [k['name'] for k in keys])
        for i, k in enumerate(keys):
            log.debug('%2d) %s', i+1, k['fingerprint'])
        pubs = [util.frame(k['blob']) + util.frame(k['name']) for k in keys]
        return util.frame(code, num, *pubs)