docs: @Override
    public void setChildren(Tree[] children) {
      if (children == null || children.length == 0) {
        this.children = ZERO_TGN_CHILDREN;
      } else {
        if (children instanceof TreeGraphNode[]) {
          this.children = (TreeGraphNode[]) children;
        } else {
          this.children = new TreeGraphNode[children.length];
          for (int i = 0; i < children.length; i++) {
            this.children[i] = (TreeGraphNode)children[i];
          }
        }
      }
    }