code: def reporter():
      _reporter = Reporter()
      _reporter.set_epoch(1)
      with _reporter.observe("valid") as sub:
          sub.register({"acc": 0.4})
          sub.next()
  
      _reporter.set_epoch(2)
      with _reporter.observe("valid") as sub:
          sub.register({"acc": 0.5})
          sub.next()
  
      _reporter.set_epoch(3)
      with _reporter.observe("valid") as sub:
          sub.register({"acc": 0.6})
          sub.next()
  
      return _reporter
  
imports: import pytest
  import torch
  from espnet2.main_funcs.average_nbest_models import average_nbest_models
  from espnet2.train.reporter import Reporter
label_desc: Use image node_id 1 for calling a global function with example usage: reporter() and returns: _reporter