`sig
val cast : 'a Gobject.obj -> Gtk.tree_item Gtk.obj
module S = GtkBrokenProps.TreeItem.S
external set_subtree :
[> `treeitem ] Gtk.obj -> [> `widget ] Gtk.obj -> unit
= "ml_gtk_tree_item_set_subtree"
external remove_subtree : [> `treeitem ] Gtk.obj -> unit
= "ml_gtk_tree_item_remove_subtree"
external collapse : [> `treeitem ] Gtk.obj -> unit
= "ml_gtk_tree_item_collapse"
external expand : [> `treeitem ] Gtk.obj -> unit
= "ml_gtk_tree_item_expand"
external create_with_label : string -> Gtk.tree_item Gtk.obj
= "ml_gtk_tree_item_new_with_label"
val create : ?label:string -> unit -> Gtk.tree_item Gtk.obj
external subtree : [> `treeitem ] Gtk.obj -> Gtk.tree Gtk.obj
= "ml_GTK_TREE_ITEM_SUBTREE"
end`