code: public static <T> IndexedPeekIterator<T> newIndexedPeekIterator(
        Iterable<T> iter) {
      return new IndexedPeekIterator<T>(iter.iterator());
    }
docs: Creates an {@link IndexedPeekIterator} by given Iterable.
  
  @param <T>
  the type of elements
  @param iter
  any Iterable
  @return an {@link IndexedPeekIterator}