code: func (v *TreeView) GetModel() (*TreeModel, error) {
  	c := C.gtk_tree_view_get_model(v.native())
  	if c == nil {
  		return nil, nil
  	}
  	return wrapTreeModel(glib.Take(unsafe.Pointer(c))), nil
  }
docs: // GetModel is a wrapper around gtk_tree_view_get_model().