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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 key_summary(keyjar, issuer):
 """ Return a text representation of the keyjar. :param keyjar: A :py:class:`oidcmsg.key_jar.KeyJar` instance :param issuer: Which key owner that we are looking at :return: A text representation of the keys """

    try:
        kbl = keyjar[issuer]
    except KeyError:
        return ''
    else:
        key_list = []
        for kb in kbl:
            for key in kb.keys():
                if key.inactive_since:
                    key_list.append(
                        '*{}:{}:{}'.format(key.kty, key.use, key.kid))
                else:
                    key_list.append(
                        '{}:{}:{}'.format(key.kty, key.use, key.kid))
        return ', '.join(key_list)