gtk/tree_view.go
func (v *TreeView) AppendColumn(column *TreeViewColumn) int {
	c := C.gtk_tree_view_append_column(v.native(), column.native())
	return int(c)
}
func (v *TreeView) AppendColumn(column *TreeViewColumn) int {
	c := C.gtk_tree_view_append_column(v.native(), column.native())
	return int(c)
}
// AppendColumn is a wrapper around gtk_tree_view_append_column().