@Nonnull
  public <T> Optional<T> lastEventId(final Class<T> type) {
    return lastEventId.toOptional(type);
  }
@Nonnull
  public <T> Optional<T> lastEventId(final Class<T> type) {
    return lastEventId.toOptional(type);
  }
@ Nonnull public < T > Optional < T > lastEventId ( final Class < T > type ) { return lastEventId . toOptional ( type ) ; }
Server sent event will send a Last-Event-ID header if the server goes down.

@param type Last event id type.
@param <T> Event id type.
@return Last event id.
Server sent event will send a Last - Event - ID header if the server goes down .