pub trait CSSGroupingRuleMethods<D: DomTypes> {
// Required methods
fn CssRules(&self, cx: &mut JSContext) -> DomRoot<D::CSSRuleList>;
fn InsertRule(
&self,
cx: &mut JSContext,
rule: DOMString,
index: u32,
) -> Fallible<u32>;
fn DeleteRule(&self, cx: &mut JSContext, index: u32) -> Fallible<()>;
}