code: func (v *view) setBit(rowID, columnID uint64) (changed bool, err error) {
  	shard := columnID / ShardWidth
  	frag, err := v.CreateFragmentIfNotExists(shard)
  	if err != nil {
  		return changed, err
  	}
  	return frag.setBit(rowID, columnID)
  }
docs: // setBit sets a bit within the view.