code: private String lookupItemName(String itemName, String suffix, boolean autoAdd) {
          return lookupItemName(itemName + "." + suffix, autoAdd);
      }
docs: Performs a case-insensitive lookup of the item name + suffix in the index.
  
  @param itemName Item name
  @param suffix Item suffix
  @param autoAdd If true and item name not in index, add it.
  @return Item name with suffix as stored internally