docs: public static <E> Map<Integer, E> indexed(Iterable<E> self, int offset) {
          Map<Integer, E> result = new LinkedHashMap<Integer, E>();
          Iterator<Tuple2<Integer, E>> indexed = indexed(self.iterator(), offset);
          while (indexed.hasNext()) {
              Tuple2<Integer, E> next = indexed.next();
              result.put(next.getFirst(), next.getSecond());
          }
          return result;
      }