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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 metadata_urls(identifiers, protocol=None, hosts=None):
 """An Archive.org metadata URL generator. :param identifiers: A set of Archive.org identifiers for which to make metadata URLs. :type identifiers: iterable :param protocol: (optional) The HTTP protocol to use. "https://" is used by default. :type protocol: str :param hosts: (optional) A set of hosts. A host will be chosen at random. The default host is "archive.org". :type hosts: iterable :returns: A generator yielding Archive.org metadata URLs. """

    for identifier in identifiers:
        path = '/metadata/{}'.format(identifier)
        url = make_url(path, protocol, hosts)
        yield url