combine props with derived props.rs

combineprops.rs

fn properties() -> &'static [ParamSpec] {
            static PROPERTIES: Lazy<Vec<ParamSpec>> =
                Lazy::new(|| {
                    let props = vec![
                    glib::ParamSpecEnum::builder::<crate::NodeType>("nodetype")
                        .default_value(NodeType::Undefined)
                        .build(),
                    ];
                    let derived_props = PwNodeObject::derived_properties();
                    [props, derived_props.to_vec()].concat()
                }
                );

                PROPERTIES.as_ref()
        }