Trait NamedNodeMapMethods 
Source pub(crate) trait NamedNodeMapMethods<D>{
    // Required methods
    fn Length(&self) -> u32;
    fn Item(&self, index: u32) -> Option<Root<Dom<<D as DomTypes>::Attr>>>;
    fn GetNamedItem(
        &self,
        qualifiedName: DOMString,
    ) -> Option<Root<Dom<<D as DomTypes>::Attr>>>;
    fn GetNamedItemNS(
        &self,
        namespace: Option<DOMString>,
        localName: DOMString,
    ) -> Option<Root<Dom<<D as DomTypes>::Attr>>>;
    fn SetNamedItem(
        &self,
        attr: &<D as DomTypes>::Attr,
    ) -> Result<Option<Root<Dom<<D as DomTypes>::Attr>>>, Error>;
    fn SetNamedItemNS(
        &self,
        attr: &<D as DomTypes>::Attr,
    ) -> Result<Option<Root<Dom<<D as DomTypes>::Attr>>>, Error>;
    fn RemoveNamedItem(
        &self,
        qualifiedName: DOMString,
    ) -> Result<Root<Dom<<D as DomTypes>::Attr>>, Error>;
    fn RemoveNamedItemNS(
        &self,
        namespace: Option<DOMString>,
        localName: DOMString,
    ) -> Result<Root<Dom<<D as DomTypes>::Attr>>, Error>;
    fn IndexedGetter(
        &self,
        index: u32,
    ) -> Option<Root<Dom<<D as DomTypes>::Attr>>>;
    fn SupportedPropertyNames(&self) -> Vec<DOMString>;
    fn NamedGetter(
        &self,
        qualifiedName: DOMString,
    ) -> Option<Root<Dom<<D as DomTypes>::Attr>>>;
}