Additional tests for attributes and model booosted rounds. (#9962)

src/learner.cc

@@ -535,8 +535,7 @@ class LearnerConfiguration : public Learner {
 
     tparam_.booster = get<String>(gradient_booster["name"]);
     if (!gbm_) {
-      gbm_.reset(GradientBooster::Create(tparam_.booster,
-                                         &ctx_, &learner_model_param_));
+      gbm_.reset(GradientBooster::Create(tparam_.booster, &ctx_, &learner_model_param_));
     }
     gbm_->LoadConfig(gradient_booster);
 
@@ -1095,6 +1094,11 @@ class LearnerIO : public LearnerConfiguration {
     std::vector<std::pair<std::string, std::string> > extra_attr;
     mparam.contain_extra_attrs = 1;
 
+    if (!this->feature_names_.empty() || !this->feature_types_.empty()) {
+      LOG(WARNING) << "feature names and feature types are being disregarded, use JSON/UBJSON "
+                      "format instead.";
+    }
+
     {
       // Similar to JSON model IO, we save the objective.
       Json j_obj { Object() };