docs: def _setup_output_metrics(self, engine):
          """Helper method to setup metrics to log
          """
          metrics = {}
          if self.metric_names is not None:
              for name in self.metric_names:
                  if name not in engine.state.metrics:
                      warnings.warn("Provided metric name '{}' is missing "
                                    "in engine's state metrics: {}".format(name, list(engine.state.metrics.keys())))
                      continue
                  metrics[name] = engine.state.metrics[name]
  
          if self.output_transform is not None:
              output_dict = self.output_transform(engine.state.output)
  
              if not isinstance(output_dict, dict):
                  output_dict = {"output": output_dict}
  
              metrics.update({name: value for name, value in output_dict.items()})
          return metrics