code: public JQMListDivider findDividerByTag(Object tag) {
          if (tag == null) return null;
          for (int k = 0; k < list.getWidgetCount(); k++) {
              Widget w = list.getWidget(k);
              if (isDivider(w) && tag.equals(((JQMListDivider) w).getTag())) {
                  return (JQMListDivider) w;
              }
          }
          return null;
      }
docs: Find the divider with the given tag. This method will search all the dividers and return the first divider
  found with the given tag.
  
  @return the divider with the given tag (if found, or null otherwise).