question: private static void add ( String optionsKey , Map < String , List < Object > > map , String key , List < Object > values ) { if ( key != null ) { if ( values == null ) { add ( map , optionsKey , key ) ; } else { List < Object > old = map . get ( key ) ; if ( old == null ) { map . put ( key , values ) ; } else { old . addAll ( values ) ; } } } }
target:  If key is null, the method does nothing. Otherwise, if values is null, the key is an option name and therefore added to the map as an option. If values is not null, the key is an operand name and the values are added as operand values --- merged with existing operand values if there are any.