Interface java.util.concurrent.`CompletionStage`

Added Methods
`CompletionStage<T>` `exceptionallyAsync`(`Function<Throwable,` `?, extends, T>`)
`CompletionStage<T>` `exceptionallyAsync`(`Function<Throwable,` `?, extends, T>, Executor`)
`CompletionStage<T>` `exceptionallyCompose`(`Function<Throwable,` `CompletionStage<T>>`)
`CompletionStage<T>` `exceptionallyComposeAsync`(`Function<Throwable,` `CompletionStage<T>>`)
`CompletionStage<T>` `exceptionallyComposeAsync`(`Function<Throwable,` `CompletionStage<T>>, Executor`)

Interface java.util.concurrent.CompletionStage