private static function set_filter_callbacks( $filter, $callbacks ) {
		global $wp_filter;

		if ( ! isset( $wp_filter[ $filter ] ) && class_exists( 'WP_Hook' ) ) {
			$wp_filter[ $filter ] = new \WP_Hook;
		}

		if ( is_a( $wp_filter[ $filter ], 'WP_Hook' ) ) {
			$wp_filter[ $filter ]->callbacks = $callbacks;
		} else {
			$wp_filter[ $filter ] = $callbacks;
		}
	}