code: func (f *fragment) rowFromStorage(rowID uint64) *Row {
  	// Only use a subset of the containers.
  	// NOTE: The start & end ranges must be divisible by container width.
  	data := f.storage.OffsetRange(f.shard*ShardWidth, rowID*ShardWidth, (rowID+1)*ShardWidth)
  
  	// Reference bitmap subrange in storage. We Clone() data because otherwise
  	// row will contain pointers to containers in storage. This causes
  	// unexpected results when we cache the row and try to use it later.
  	// Basically, since we return the Row and release the fragment lock, the
  	// underlying fragment storage could be changed or snapshotted and thrown
  	// out at any point.
  	row := &Row{
  		segments: []rowSegment{{
  			data:     *data.Clone(),
  			shard:    f.shard,
  			writable: false, // this Row will probably be cached and shared, so it must be read only.
  		}},
  	}
  	row.invalidateCount()
  
  	return row
  }
docs: // rowFromStorage clones a row data out of fragment storage and returns it as a
  // Row object.