def as_rack_controller(self):
        """Convert to a `RackController` object.

        `node_type` must be `NodeType.RACK_CONTROLLER` or
        `NodeType.REGION_AND_RACK_CONTROLLER`.
        """
        if self.node_type not in [
                NodeType.RACK_CONTROLLER, NodeType.REGION_AND_RACK_CONTROLLER]:
            raise ValueError(
                'Cannot convert to `RackController`, node_type is not a '
                'rack controller.')
        return self._origin.RackController(self._data)
Convert to a `RackController` object.

        `node_type` must be `NodeType.RACK_CONTROLLER` or
        `NodeType.REGION_AND_RACK_CONTROLLER`.