} else { CheckRuleForAttributes(aRule);
CSSStyleSheetImpl::PrependStyleRule(nsICSSRule* aRule){  NS_PRECONDITION(nsnull != aRule, "null arg");  if (NS_SUCCEEDED(WillDirty())) {    if (! mInner->mOrderedRules) {      NS_NewISupportsArray(&(mInner->mOrderedRules));    }    if (mInner->mOrderedRules) {      mInner->mOrderedRules->InsertElementAt(aRule, 0);      aRule->SetStyleSheet(this);      DidDirty();      PRInt32 type;      aRule->GetType(type);      if (nsICSSRule::NAMESPACE_RULE == type) {        // no api to prepend a namespace (ugh), release old ones and re-create them all        mInner->RebuildNameSpaces();      }    }  }  return NS_OK;}