code: def update_launch_config(self, scaling_group, server_name=None, image=None,
              flavor=None, disk_config=None, metadata=None, personality=None,
              networks=None, load_balancers=None, key_name=None, config_drive=False,
              user_data=None):
          
          return self._manager.update_launch_config(scaling_group,
                  server_name=server_name, image=image, flavor=flavor,
                  disk_config=disk_config, metadata=metadata,
                  personality=personality, networks=networks,
                  load_balancers=load_balancers, key_name=key_name,
                  config_drive=config_drive, user_data=user_data)
docs: Updates the server launch configuration for an existing scaling group.
          One or more of the available attributes can be specified.
  
          NOTE: if you specify metadata, it will *replace* any existing metadata.
          If you want to add to it, you either need to pass the complete dict of
          metadata, or call the update_launch_metadata() method.