public function build_one_image_sitemap( $number, $from_id ) {
    $last_post_id   = $from_id;
    $any_posts_left = true;

    if ( $this->logger ) {
      $debug_name = jp_sitemap_filename( JP_IMAGE_SITEMAP_TYPE, $number );
      $this->logger->report( "-- Building $debug_name" );
    }

    $buffer = new Jetpack_Sitemap_Buffer_Image(
      JP_SITEMAP_MAX_ITEMS,
      JP_SITEMAP_MAX_BYTES
    );

    // Add as many items to the buffer as possible.
    while ( false === $buffer->is_full() ) {
      $posts = $this->librarian->query_images_after_id(
        $last_post_id,
        JP_SITEMAP_BATCH_SIZE
      );

      if ( null == $posts ) { // WPCS: loose comparison ok.
        $any_posts_left = false;
        break;
      }

      foreach ( $posts as $post ) {
        $current_item = $this->image_post_to_sitemap_item( $post );

        if ( true === $buffer->append( $current_item['xml'] ) ) {
          $last_post_id = $post->ID;
          $buffer->view_time( $current_item['last_modified'] );
        } else {
          break;
        }
      }
    }

    // If no items were added, return false.
    if ( true === $buffer->is_empty() ) {
      return false;
    }

    // Store the buffer as the content of a jp_sitemap post.
    $this->librarian->store_sitemap_data(
      $number,
      JP_IMAGE_SITEMAP_TYPE,
      $buffer->contents(),
      $buffer->last_modified()
    );

    /*
		 * Now report back with the ID of the last post to be
		 * successfully added and whether there are any posts left.
		 */
    return array(
      'last_id'       => $last_post_id,
      'any_left'      => $any_posts_left,
      'last_modified' => $buffer->last_modified(),
    );
  }