code: def test_reduce_trainer_metrics_dict():
      dict_dict_trainer_metrics = {
          "feature_name": {
              "metric_name": [
                  metric_utils.TrainerMetric(epoch=1, step=2, value=10)
              ]
          }
      }
  
      result = metric_utils.reduce_trainer_metrics_dict(
          dict_dict_trainer_metrics
      )
  
      assert result == {"feature_name": {"metric_name": [10]}}
  
file_path: ludwig/tests/ludwig/utils/test_metric_utils.py
imports: from collections import OrderedDict
  import torch
  from ludwig.utils import metric_utils
  from ludwig.utils.metric_utils import TrainerMetric
label_desc: Use image node_id 4 for calling a global function with example usage: test_reduce_trainer_metrics_dict() without return types