* Removes the ajax callback for the meta box.
	 *
	 * @since 4.7.0
	 */
	public function remove_hooks() {
		remove_filter( 'wp_ajax_add-' . $this->name, '_wp_ajax_add_hierarchical_term' );
	}

	/**
	 * Gets the REST API controller for this taxonomy.
	 *
	 * Will only instantiate the controller class once per request.
	 *
	 * @since 5.5.0
	 *
	 * @return WP_REST_Controller|null The controller instance, or null if the taxonomy
	 *                                 is set not to show in rest.
	 */
	public function get_rest_controller() {
		if ( ! $this->show_in_rest ) {
			return null;
		}

		$class = $this->rest_controller_class ? $this->rest_controller_class : WP_REST_Terms_Controller::class;

		if ( ! class_exists( $class ) ) {
			return null;
		}

		if ( ! is_subclass_of( $class, WP_REST_Controller::class ) ) {
			return null;
		}

		if ( ! $this->rest_controller ) {
			$this->rest_controller = new $class( $this->name );
		}

		if ( ! ( $this->rest_controller instanceof $class ) ) {
			return null;
		}

		return $this->rest_controller;
	}
}