class_docstr: Tests for `migrate_event`.
class_docstr_tok: ["Tests","for","`","migrate_event","`","."]
code: def test_irrelevant_event_passes_through(self):
      old_event = event_pb2.Event()
      old_event.file_version = "brain.Event:wow"
  
      new_events = self._migrate_event(old_event)
      self.assertLen(new_events, 1)
      self.assertIs(new_events[0], old_event)
  
imports: import os
  import numpy
  import tensorflow
  from tensorboard import dataclass_compat
  from tensorboard.backend.event_processing import event_file_loader
  from tensorboard.compat.proto import event_pb2
  from tensorboard.compat.proto import graph_pb2
  from tensorboard.compat.proto import summary_pb2
  from tensorboard.plugins.audio import metadata
  from tensorboard.plugins.audio import summary
  from tensorboard.plugins.graph import metadata
  from tensorboard.plugins.histogram import metadata
  from tensorboard.plugins.histogram import summary
  from tensorboard.plugins.hparams import metadata
  from tensorboard.plugins.hparams import summary_v2
  from tensorboard.plugins.pr_curve import metadata
  from tensorboard.plugins.pr_curve import summary
  from tensorboard.plugins.scalar import metadata
  from tensorboard.plugins.scalar import summary
  from tensorboard.util import tensor_util
  from tensorboard.util import test_util
label_desc: Use image node_id 2 for calling the MigrateEventTest obj's underlying member method code with example usage: obj.test_irrelevant_event_passes_through() without return types