public void addValueList ( String key , String value ) { Objects . requireNonNull ( key , Required . KEY . toString ( ) ) ; if ( ! valueMap . containsKey ( key ) ) { List < String > values = new ArrayList <> ( ) ; values . add ( value ) ; valueMap . put ( key , values ) ; } else { List < String > values = valueMap . get ( key ) ; values . add ( value ) ; valueMap . put ( key , values ) ; } }
Adds an additional item to the value list