docs: def _default_key_setter(self, name, subject):
          """
          This method is used only when there is a custom key_setter set.
  
          Do not override this method.
          """
          if is_config_item(subject):
              self.add_item(name, subject)
          elif is_config_section(subject):
              self.add_section(name, subject)
          else:
              raise TypeError(
                  'Section items can only be replaced with items, '
                  'got {type}. To set item value use ...{name}.value = <new_value>'.format(
                      type=type(subject),
                      name=name,
                  )
              )