OperatorCoordinator.SubtaskGateway (Flink : Runtime 2.1.0 API)

Enclosing interface:

OperatorCoordinator
```
public static interface OperatorCoordinator.SubtaskGateway
```
The SubtaskGateway is the way to interact with a specific parallel instance of the Operator (an Operator subtask), like sending events to the operator.

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`ExecutionAttemptID`	`getExecution()`	Gets the execution attempt for the subtask execution attempt that this gateway communicates with.
`int`	`getSubtask()`	Gets the subtask index of the parallel operator instance this gateway communicates with.
`CompletableFuture<Acknowledge>`	`sendEvent(OperatorEvent evt)`	Sends an event to the parallel subtask with the given subtask index.

- Method Detail
  - sendEvent
```
CompletableFuture<Acknowledge> sendEvent(OperatorEvent evt)
```
    Sends an event to the parallel subtask with the given subtask index.
    The returned future is completed successfully once the event has been received by the target TaskManager. The future is completed exceptionally if the event cannot be sent. That includes situations where the target task is not running.
  - getExecution
```
ExecutionAttemptID getExecution()
```
    Gets the execution attempt for the subtask execution attempt that this gateway communicates with.
  - getSubtask
```
int getSubtask()
```
    Gets the subtask index of the parallel operator instance this gateway communicates with.