code: def on_validation_end(self, metrics: Dict[str, Any]) -> None:
      self.validation_metrics.append(metrics)
  
imports: import random
  from typing import Any, Dict, Tuple
  import numpy
  import torch
  from torch import nn
  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