* Gets the expression that the string filter uses to
* obtain strings from items.
*
- * Returns: (transfer none): a `GtkExpression`
+ * Returns: (transfer none) (nullable): a `GtkExpression`
*/
GtkExpression *
gtk_string_filter_get_expression (GtkStringFilter *self)
/**
* gtk_string_filter_set_expression: (attributes org.gtk.Method.set_property=expression)
* @self: a `GtkStringFilter`
- * @expression: a `GtkExpression`
+ * @expression: (nullable): a `GtkExpression`
*
* Sets the expression that the string filter uses to
* obtain strings from items.