SupportsRowLevelUpdate.RowLevelUpdateInfo (Flink : Table : Common 2.0-preview1 API)

Enclosing interface:

SupportsRowLevelUpdate
```
@PublicEvolving
public static interface SupportsRowLevelUpdate.RowLevelUpdateInfo
```
The information that guides the planner on how to rewrite the update statement.

Method Summary

All Methods Instance Methods Default Methods
Modifier and Type	Method	Description
`default SupportsRowLevelUpdate.RowLevelUpdateMode`	`getRowLevelUpdateMode()`	Planner will rewrite the update statement to query base on the `SupportsRowLevelUpdate.RowLevelUpdateMode`, keeping the query of update unchanged by default(in `UPDATED_ROWS` mode), or changing the query to union the updated rows and the other rows (in `ALL_ROWS` mode).
`default Optional<List<Column>>`	`requiredColumns()`	The required columns by the sink to perform row-level update.

- Method Detail
  - requiredColumns
```
default Optional<List<Column>> requiredColumns()
```
    The required columns by the sink to perform row-level update. The rows consumed by sink will contain the required columns in order. If return Optional.empty(), it will contain all columns.
  - getRowLevelUpdateMode
```
default SupportsRowLevelUpdate.RowLevelUpdateMode getRowLevelUpdateMode()
```
    Planner will rewrite the update statement to query base on the SupportsRowLevelUpdate.RowLevelUpdateMode, keeping the query of update unchanged by default(in `UPDATED_ROWS` mode), or changing the query to union the updated rows and the other rows (in `ALL_ROWS` mode).
    Take the following SQL as an example:
    UPDATE t SET x = 1 WHERE y = 2;
    
    If returns SupportsRowLevelUpdate.RowLevelUpdateMode.UPDATED_ROWS, the sink will get the update after rows which match the filter [y = 2].
    If returns SupportsRowLevelUpdate.RowLevelUpdateMode.ALL_ROWS, the sink will get both the update after rows which match the filter [y = 2] and the other rows that don't match the filter [y = 2].
    Note: All rows will have RowKind#UPDATE_AFTER when RowLevelUpdateMode is UPDATED_ROWS, and RowKind#INSERT when RowLevelUpdateMode is ALL_ROWS.