private SearchFieldTreeNode[] getIndexesOfReusableDropdownChildren(SearchFieldTreeNode parent) {
    Vector reusableDropdownNodes = new Vector();
    for (int i = 0; i < parent.getChildCount(); ++i) {
      SearchFieldTreeNode child = (SearchFieldTreeNode) parent.getChildAt(i);
      if (!child.isSearchableFieldChoiceItemNode()) continue;
      SearchableFieldChoiceItem choice = child.getChoiceItem();
      FieldSpec spec = choice.getSpec();
      if (spec.getReusableChoicesCodes().length == 0) continue;
      reusableDropdownNodes.add(child);
    }

    return (SearchFieldTreeNode[]) reusableDropdownNodes.toArray(new SearchFieldTreeNode[0]);
  }