code: public static <T> Mono<T> allOf(Mono<T>... fts) {
  
          return Mono.from(Future.allOf(futures(fts)));
      }
docs: Wait until all the provided Future's to complete
  
  @see CompletableFuture#allOf(CompletableFuture...)
  
  @param fts Monos to  wait on
  @return Mono that completes when all the provided Futures Complete. Empty Future result, or holds an Exception
  from a provided Future that failed.