code: def on_validation_end(self, metrics: Dict[str, Any]) -> None:
      self.validation_metrics.append(metrics)
  
file_path: determined/harness/tests/experiment/fixtures/pytorch_identity/model_def.py
imports: from typing import Any, Dict, Tuple
  import torch.utils.data
  from determined import pytorch
label_desc: Use image node_id 2 for calling the MetricsCallback obj's underlying member method code with example usage: obj.on_validation_end(metrics) without return types