public Href without(final Object key){
  final SortedMap<String,List<String>> map=new TreeMap<>(this.params);
  map.remove(key.toString());
  return new Href(this.uri,map);
}

public Href without ( final Object key ) { final SortedMap < String , List < String > > map = new TreeMap < > ( this . params ) ; map . remove ( key . toString ( ) ) ; return new Href ( this . uri , map ) ; }
without this query param .
