HistoricFeedStatusCallback (eBus Feed 7.4.0 API)

Functional Interface:

This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.
```
@FunctionalInterface
public interface HistoricFeedStatusCallback
```
An eBus client implementing IEHistoricSubscriber may choose to implement this functional interface as a private method instead of implementing the public IEHistoricSubscriber.feedStatus(PublishStatusEvent, EHistoricSubscribeFeed) method. This private HistoricFeedStatusCallback method is then passed to EHistoricSubscribeFeed.Builder.statusCallback(HistoricFeedStatusCallback).
Note: this callback may only be set when building an EHistoricSubscribeFeed instance. Once built, the publisher feed status callback target may not be changed.

Note: failure to implement IEHistoricSubscriber.statusCallback or to pass a HistoricFeedStatusCallback method to Builder.statusCallback results in a Builder.build() failure.

Author:

Charles W. Rapp

See Also:

EHistoricSubscribeFeed, HistoricNotifyCallback, HistoricFeedDoneCallback

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`void`	`call(PublishStatusEvent event, EHistoricSubscribeFeed feed)`	eBus calls this method to inform subscriber that the publisher feed state is either `EFeedState.UP` or `EFeedState.DOWN`.

- Method Detail
  - call
```
void call(PublishStatusEvent event,
          EHistoricSubscribeFeed feed)
```
    eBus calls this method to inform subscriber that the publisher feed state is either EFeedState.UP or EFeedState.DOWN.
    
    Parameters:
    
    event - publish status event contains the publisher's latest feed state for the given message key.
    
    feed - historic subscribe feed.