public static void addIfEmpty(List<List<DimensionalItemObject>> list){
  if (list != null && list.size() == 0) {
    list.add(Arrays.asList(new DimensionalItemObject[0]));
  }
}

public static void addIfEmpty ( List < List < DimensionalItemObject > > list ) { if ( list != null && list . size ( ) == 0 ) { list . add ( Arrays . asList ( new DimensionalItemObject [ 0 ] ) ) ; } }
adds an empty list of dimensionalitemobjects to the given list if empty .
