AsyncTriggerConverter (Flink : Runtime 2.2.0 API)

```
@Internal
public interface AsyncTriggerConverter
```
A converter from Trigger to AsyncTrigger.
Basic triggers (e.g., CountTrigger) are directly converted to their async version.
Async-support triggers which implement AsyncTriggerConvertable (e.g., ProcessingTimeoutTrigger) will use self-defined async version.
Other triggers are wrapped as an AsyncTrigger, whose internal functions are executed in sync mode.

Nested Class Summary

Nested Classes
Modifier and Type	Interface	Description
`static class`	`AsyncTriggerConverter.UserDefinedAsyncTrigger<T,W extends Window>`	Convert non-support user-defined trigger to `AsyncTrigger`.

Method Summary

All Methods Static Methods Instance Methods Default Methods
Modifier and Type	Method	Description
`default Object`	`convertToAsync()`	Convert to an `AsyncTrigger`.
`static <T,W extends Window> AsyncTrigger<T,W>`	`convertToAsync(Trigger<T,W> trigger)`

- Method Detail
  - convertToAsync
```
@Nonnull
default Object convertToAsync()
```
    Convert to an AsyncTrigger. The default implementation is only a wrapper of the trigger, whose behaviours are all sync.
    TODO: Return AsyncTrigger if AsyncTrigger becomes @PublicEvolving.
    
    Returns:
    
    The AsyncTrigger for async state processing.
  - convertToAsync
```
static <T,W extends Window> AsyncTrigger<T,W> convertToAsync(Trigger<T,W> trigger)
```