public static @NotNull JBIterable<TreeNode> nodeChildren(@Nullable TreeNode treeNode) {
    int count = treeNode == null ? 0 : treeNode.getChildCount();
    return count == 0 ? JBIterable.empty() : NUMBERS.take(count).map(index -> treeNode.getChildAt(index));
  }
public static @NotNull JBIterable<TreeNode> nodeChildren(@Nullable TreeNode treeNode)