code: public JQMListItem findItemByTag(Object tag) {
          if (tag == null) return null;
          List<JQMListItem> lst = getItems();
          for (JQMListItem i : lst) {
              if (i == null) continue;
              if (tag.equals(i.getTag())) return i;
          }
          return null;
      }
docs: Find the list item with the given tag. This method will search all the items and return
  the first item found with the given tag.
  
  @return the list item with the given tag (if found, or null otherwise).