code: public <T> T withTransaction(@NotNull Propagation propagation,
                                   @NotNull Isolation isolation,
                                   @NotNull TransactionCallback<T> callback) {
  
          TransactionSettings settings = new TransactionSettings();
          settings.setPropagation(propagation);
          settings.setIsolation(isolation);
  
          return withTransaction(settings, callback);
      }
docs: Executes a block of code with given propagation and isolation.