docs: function moveArticleAfter(summary, origin, afterTarget) {
      // Coerce to level
      var originLevel = is.string(origin)? origin : origin.getLevel();
      var afterTargetLevel = is.string(afterTarget)? afterTarget : afterTarget.getLevel();
      var article = summary.getByLevel(originLevel);
  
      var targetLevel = increment(afterTargetLevel);
  
      if (targetLevel < origin) {
          // Remove first
          var removed = removeArticle(summary, originLevel);
          // Insert then
          return insertArticle(removed, article, targetLevel);
      } else {
          // Insert right after first
          var inserted = insertArticle(summary, article, targetLevel);
          // Remove old one
          return removeArticle(inserted, originLevel);
      }
  }