Returns {@code true} if this CompletableFuture completed
exceptionally, in any way. Possible causes include
cancellation, explicit invocation of {@code
completeExceptionally}, and abrupt termination of a
CompletionStage action.
@return {@code true} if this CompletableFuture completed
exceptionally
Returns {@code true} if this CompletableFuture completed exceptionally, in any way. Possible causes include cancellation, explicit invocation of {@code completeExceptionally}, and abrupt termination of a CompletionStage action.
@return {@code true} if this CompletableFuture completed exceptionally