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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 __check_config_key(self, key):
 """Check whether the key is valid. A valid key has the schema <section>.<option>. Keys supported are listed in CONFIG_OPTIONS dict. :param key: <section>.<option> key """

        try:
            section, option = key.split('.')
        except (AttributeError, ValueError):
            return False

        if not section or not option:
            return False

        return section in Config.CONFIG_OPTIONS and\
            option in Config.CONFIG_OPTIONS[section]