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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 is_user_reseller_admin(self, req, account, user):
 """Returns True if the user is a .reseller_admin. :param account: account user is part of :param user: the user :returns: True if user .reseller_admin, False if user is not a reseller_admin and None if the user doesn't exist. """

        req.credentials_valid = True
        user_json = self.get_user_detail(req, account, user)
        if user_json is None:
            req.credentials_valid = False
            return False

        user_detail = json.loads(user_json)

        return '.reseller_admin' in (g['name'] for g in user_detail['groups'])