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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 _pushdate_urls(cls, pushdate, branch, target_platform):
 """Multiple entries exist per push date. Iterate over all until a working entry is found"""

        url_base = cls.URL_BASE + '/namespaces/gecko.v2.mozilla-' + branch + '.pushdate.' + pushdate

        try:
            base = HTTP_SESSION.post(url_base, json={})
            base.raise_for_status()
        except requests.exceptions.RequestException as exc:
            raise FetcherException(exc)

        product = 'mobile' if 'android' in target_platform else 'firefox'
        json = base.json()
        for namespace in sorted(json['namespaces'], key=lambda x: x['name']):
            yield cls.URL_BASE + '/task/' + namespace['namespace'] + '.' + product + '.' + target_platform