EsFutureListener
The listener is registered on a future and handles value/error completions
STATE\     nextListener - <EsFutureListener> Listeners on the same future are linked through this link.\     result - <EsFutureImpl> The future to complete when this listener is activated.\     state - <Integer> Which fields means what.\     handler - <Block> Used for then/whenDone callback and error test\     errorHandler - <Block> Used for error callbacks.\
Class Methods
    catchError:onError:test:
  Answer a new listener that handles errors emitted by a future
     Arguments:
        aResult - <EsFutureImpl>
        onError - <Block>
        onErrorTest - <Block>
     Answers:
        <EsFutureListener>
 
    then:onValue:onError:
  Answer a new listener that handles a future's completion value
     Arguments:
        aResult - <EsFutureImpl>
        onValue - <Block>
        onError - <Block>
     Answers:
        <EsFutureListener>
 
    whenComplete:handler:
  Answer a new listener whose handler is called when a future completes
     Arguments:
        aResult - <EsFutureImpl>
        aHandler - <Block>
     Answers:
        <EsFutureListener>
 Instance Methods
    hasErrorHandler
  Whether this listener has an error handler.
     This method must only be called if the listener #handlesError
     Answers:
        <Boolean>
 
    result
  Answer the future to complete when this listener is activated
     Answers:
        <EsFutureImpl>
 Last modified date: 02/23/2021