code: def unset(self, key):
          
          key = key.strip().upper()
          if key not in dir(default_settings) and key not in self._defaults:
              self.logger.debug("Unset %s", key)
              delattr(self, key)
              self.store.pop(key, None)
docs: Unset on all references
  
          :param key: The key to be unset