Observer (Yamcs :: API 5.4.3 API)

```
public interface Observer<T>
```

Method Summary

All Methods Instance Methods Abstract Methods Default Methods
Modifier and Type	Method	Description
`void`	`complete()`	Mark the successful end.
`default void`	`complete(T message)`	Shortcut for:
`void`	`completeExceptionally(Throwable t)`	Complete with an exception.
`default boolean`	`isCancelled()`	Returns whether this call has been cancelled by the remote peer
`void`	`next(T message)`	Emit the next message.
`default void`	`setCancelHandler(Runnable cancelHandler)`	Set a `Runnable` that will be called when the call is cancelled.

- Method Detail
  - next
```
void next(T message)
```
    Emit the next message.
  - completeExceptionally
```
void completeExceptionally(Throwable t)
```
    Complete with an exception.
  - complete
```
void complete()
```
    Mark the successful end.
  - complete
```
default void complete(T message)
```
    Shortcut for:
    next(message); complete();
  - isCancelled
```
default boolean isCancelled()
```
    Returns whether this call has been cancelled by the remote peer
  - setCancelHandler
```
default void setCancelHandler(Runnable cancelHandler)
```
    Set a Runnable that will be called when the call is cancelled. (example: peer disconnect)