rowHasChildToggled   
  ⚠️ Deprecated ⚠️
This is deprecated since version 4.10.
---Emits the ::row-has-child-toggled signal on @tree_model.
See signal@Gtk.TreeModel::row-has-child-toggled.
This should be called by models after the child state of a node changes.
Parameters
path
a GtkTreePath pointing to the changed row
iter
a valid GtkTreeIter pointing to the changed row