pub unsafe extern "C" fn gtk_font_dialog_choose_family(
    self_: *mut GtkFontDialog,
    parent: *mut GtkWindow,
    initial_value: *mut PangoFontFamily,
    cancellable: *mut GCancellable,
    callback: GAsyncReadyCallback,
    user_data: gpointer
)
Available on crate feature v4_10 only.