class GroupShardsIterator<ShardIt extends ShardIterator> implements Iterable<ShardIt> {

    private final List<ShardIt> iterators;

    /**
     * Constructs a new sorted GroupShardsIterator from the given list. Items are sorted based on their natural ordering.
     * @see PlainShardIterator#compareTo(ShardIterator)
     */
    public static <ShardIt extends ShardIterator> GroupShardsIterator<ShardIt> sortAndCreate(List<ShardIt> iterators) {
        CollectionUtil.timSort(iterators);
        return new GroupShardsIterator<>(iterators);
    }

    /**
     * Constructs a new GroupShardsIterator from the given list.
     */
    private GroupShardsIterator(List<ShardIt> iterators) {
        this.iterators = iterators;
    }

    /**
     * Returns the total number of shards within all groups
     * @return total number of shards
     */
    public int totalSize() {<FILL_FUNCTION_BODY>}

    /**
     * Returns the total number of shards plus the number of empty groups
     * @return number of shards and empty groups
     */
    public int totalSizeWith1ForEmpty() {
        int size = 0;
        for (ShardIt shard : iterators) {
            size += Math.max(1, shard.size());
        }
        return size;
    }

    /**
     * Return the number of groups
     * @return number of groups
     */
    public int size() {
        return iterators.size();
    }

    @Override
    public Iterator<ShardIt> iterator() {
        return iterators.iterator();
    }

    public ShardIt get(int index) {
        return iterators.get(index);
    }
}

        int size = 0;
        for (ShardIterator shard : iterators) {
            size += shard.size();
        }
        return size;
    
<no_super_class>