TreeModelForeachFunc   
    typealias TreeModelForeachFunc = (model: TreeModel, path: TreePath, iter: TreeIter) -> Boolean(source)
Type of the callback passed to gtk_tree_model_foreach() to iterate over the rows in a tree model.
- param - modelthe- GtkTreeModelbeing iterated
- param - paththe current- GtkTreePath
- param - iterthe current- GtkTreeIter
- return true to stop iterating, false to continue