code: def set_or_reset_runtime_param(self, key, value):
          
          if self._runtime.has_option('general', key):
              self._runtime = self._new_parser()
  
          if value is None:
              return
          settings._runtime.set('general', key.replace('tower_', ''),
                                six.text_type(value))
docs: Maintains the context of the runtime settings for invoking
          a command.
  
          This should be called by a click.option callback, and only
          called once for each setting for each command invocation.
  
          If the setting exists, it follows that the runtime settings are
          stale, so the entire runtime settings are reset.