function callback( $path = '', $site_id = 0 ) {
    $blog_id = $this->api->switch_to_blog_and_validate_user( $this->api->get_blog_id( $site_id ) );
    if ( is_wp_error( $blog_id ) ) {
      return $blog_id;
    }

    if ( ! current_user_can( 'edit_theme_options' ) ) {
      return new WP_Error( 'unauthorized', 'User is not authorized to access homepage settings', 403 );
    }

    $args = $this->input();
    if ( empty( $args ) || ! is_array( $args ) ) {
      return $this->get_current_settings();
    }

    if ( isset( $args['is_page_on_front'] ) ) {
      $show_on_front = $args['is_page_on_front'] ? 'page' : 'posts';
      update_option( 'show_on_front', $show_on_front );
    }
    if ( isset( $args['page_on_front_id'] ) ) {
      update_option( 'page_on_front', $args['page_on_front_id'] );
    }
    if ( isset( $args['page_for_posts_id'] ) ) {
      update_option( 'page_for_posts', $args['page_for_posts_id'] );
    }

    return $this->get_current_settings();
  }