See discussion in #1547 for context.
The name modifications is intended to map to the RPC method name ReadModifyWriteRow but the word modification is a synonym of mutation, so this method is poorly named. The method actually sends changes that
- increment an int (stored in BT as 8 bytes)
- append bytes to a cell value
so we should either
- Fold it into
Row.commit() as commit(append_only=True)
- Rename it to something like
Row.commit_cell_updates (or a better name than that)