pub trait Attributable {
// Required method
fn attributes(&self) -> &[Attribute];
// Provided methods
fn element_type(&self) -> Option<&str> { ... }
fn gtk_property_get(&self) -> Option<&str> { ... }
fn gtk_method_get_property(&self) -> Option<&str> { ... }
fn gtk_property_set(&self) -> Option<&str> { ... }
fn gtk_method_set_property(&self) -> Option<&str> { ... }
}