public void putMap(Map<String,List<String>> m){
  for (  String key : m.keySet()) {
    SortedSet<String> vals=get(key);
    if (vals == null) {
      vals=new TreeSet<String>();
      put(key,vals);
    }
    vals.addAll(m.get(key));
  }
}

public void putMap ( Map < String , List < String > > m ) { for ( String key : m . keySet ( ) ) { SortedSet < String > vals = get ( key ) ; if ( vals == null ) { vals = new TreeSet < String > ( ) ; put ( key , vals ) ; } vals . addAll ( m . get ( key ) ) ; } }
convenience method to merge a map < string , list < string > > .
