code: public void setChildren(List<? extends Tree> childTreesList) {
      if (childTreesList == null || childTreesList.isEmpty()) {
        setChildren(ZERO_TGN_CHILDREN);
      } else {
        int leng = childTreesList.size();
        TreeGraphNode[] childTrees = new TreeGraphNode[leng];
        childTreesList.toArray(childTrees);
        setChildren(childTrees);
      }
    }
docs: {@inheritDoc}