// Empty string for no namespace.
Empty string for no namespace.
Empty string for no namespace .
fn has_namespace(&self, ns: &<Self::Impl as SelectorImpl>::BorrowedNamespaceUrl) -> bool {
        self.query(|node| {
            if let NodeData::Element(ref e) = node.data {
                return &e.name.ns == ns;
            }
            false
        })
    }
fn has_namespace ( & self , ns : & < Self :: Impl as SelectorImpl > :: BorrowedNamespaceUrl ) -> bool { self . query ( | node | { if let NodeData :: Element ( ref e ) = node . data { return & e . name . ns == ns ; } false } ) }
Empty string for no namespace.
Empty string for no namespace .
&self
ns
&<Self::Impl as SelectorImpl>::BorrowedNamespaceUrl