Fetch and return the values for the style properties named in ... for a widget of type widget_package. get is an alias for get_style_property.

my $size = $style->get_style_property ("expander-size");

Note: The get method shadows Glib::Object::get (see "get and set" in Glib::Object). This shouldn't be a problem since Gtk2::Style defines no properties (as of gtk+ 2.16). If you have a class that's derived from Gtk2::Style and adds a property or if a new version of gtk+ adds a property to Gtk2::Style then the property can be accessed with get_property.