docs: public synchronized void setSelectedItem(final V item) {
          if(item == null) {
              setSelectedIndex(-1);
          }
          else {
              int indexOf = items.indexOf(item);
              if (indexOf != -1) {
                  setSelectedIndex(indexOf);
              }
              else if (!readOnly) {
                  updateText(item.toString());
              }
          }
      }