protected function test__sync_health() {

    $name = __FUNCTION__;

    if ( ! $this->helper_is_jetpack_connected() ) {
      // If the site is not connected, there is no point in testing Sync health.
      return self::skipped_test(
        array(
          'name'                => $name,
          'show_in_site_health' => false,
        )
      );
    }

    // Sync is enabled.
    if ( Sync_Settings::is_sync_enabled() ) {

      if ( Sync_Health::get_status() === Sync_Health::STATUS_OUT_OF_SYNC ) {
        /*
				 * Sync has experienced Data Loss.
				 */
        $description  = '<p>';
        $description .= esc_html__( 'The information synced by Jetpack ensures that Jetpack Search, Related Posts and other features are aligned with your site’s current content.', 'jetpack' );
        $description .= '</p>';
        $description .= '<p>';
        $description .= sprintf(
          '<span class="dashicons fail"><span class="screen-reader-text">%1$s</span></span> ',
          esc_html__( 'Error', 'jetpack' )
        );
        $description .= wp_kses(
          __( 'Jetpack has detected an error while syncing your site. <strong>We recommend <a id="full_sync_request_link" href="#">a full sync</a> to align Jetpack with your site data.</strong>', 'jetpack' ),
          array(
            'a'      => array(
              'id'   => array(),
              'href' => array(),
            ),
            'strong' => array(),
          )
        );
        $description .= '</p>';

        return self::failing_test(
          array(
            'name'              => $name,
            'label'             => __( 'Jetpack has detected an error syncing your site.', 'jetpack' ),
            'severity'          => 'critical',
            'action'            => Redirect::get_url( 'jetpack-contact-support' ),
            'action_label'      => __( 'Contact Jetpack Support', 'jetpack' ),
            'short_description' => __( 'Jetpack has detected an error while syncing your site. We recommend a full sync to align Jetpack with your site data.', 'jetpack' ),
            'long_description'  => $description,
          )
        );

      } else {
        // Get the Sync Queue.
        $sender     = Sync_Sender::get_instance();
        $sync_queue = $sender->get_sync_queue();

        // lag exceeds 5 minutes.
        if ( $sync_queue->lag() > 5 * MINUTE_IN_SECONDS ) {

          $description  = '<p>';
          $description .= esc_html__( 'The information synced by Jetpack ensures that Jetpack Search, Related Posts and other features are aligned with your site’s current content.', 'jetpack' );
          $description .= '</p>';
          $description .= '<p>';
          $description .= sprintf(
            '<span class="dashicons dashicons-clock" style="color: orange;"><span class="screen-reader-text">%1$s</span></span> ',
            /* translators: name, used to describe a clock icon. */
            esc_html__( 'Clock', 'jetpack' )
          );
          $description .= wp_kses(
            sprintf(
              /* translators: placeholder is a number of minutes. */
              _n(
                'Jetpack has identified a delay while syncing individual content updates. Certain features might be slower than usual, but this is only temporary while sync catches up with recent changes to your site. <strong>We’re seeing a current delay of %1$d minute.</strong>',
                'Jetpack has identified a delay while syncing individual content updates. Certain features might be slower than usual, but this is only temporary while sync catches up with recent changes to your site. <strong>We’re seeing a current delay of %1$d minutes.</strong>',
                intval( $sync_queue->lag() / MINUTE_IN_SECONDS ),
                'jetpack'
              ),
              number_format_i18n( $sync_queue->lag() / MINUTE_IN_SECONDS )
            ),
            array( 'strong' => array() )
          );
          $description .= '</p>';

          return self::informational_test(
            array(
              'name'              => $name,
              'label'             => __( 'Jetpack is experiencing a delay syncing your site.', 'jetpack' ),
              'severity'          => 'recommended',
              'action'            => null,
              'action_label'      => null,
              'short_description' => __( 'Jetpack is experiencing a delay syncing your site.', 'jetpack' ),
              'long_description'  => $description,
            )
          );

        } else {

          // Sync is Healthy.
          return self::passing_test( array( 'name' => $name ) );