Function handle_tree 

pub async fn handle_tree(
    req: HttpRequest,
    body: String,
    state: Data<AppState>,
) -> Result<HttpResponse, HaystackError>

Returns a hierarchical subtree from a root entity.

Request Grid Columns

Column	Kind	Description
root	Ref	Root entity to start tree from
maxDepth	Number	(optional) Maximum tree depth (default 10)

Response Grid Columns

All entity tags plus: depth, parentId, navId.