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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 get_setting(self, key, default=NOT_SET):
 """ Gets a setting for the key. :raise KeyError: If the key is not set and default isn't provided. """

        if self._arca is None:
            raise LazySettingProperty.SettingsNotReady
        return self._arca.settings.get(*self.get_settings_keys(key), default=default)