code: def testIndex(self):
      plugin = self.load_plugin()
      index = plugin.index_impl(
          context.RequestContext(), experiment="123"
      )
      self.assertCountEqual(["fry", "leela"], index.keys())
      self.assertCountEqual(["message", "vector"], index["fry"])
      self.assertCountEqual(["message", "vector"], index["leela"])
  
imports: import collections.abc
  import os
  import textwrap
  import numpy
  import tensorflow
  from tensorboard import plugin_util
  from tensorboard import context
  from tensorboard.backend.event_processing import data_provider
  from tensorboard.backend.event_processing import plugin_event_multiplexer
  from tensorboard.plugins import base_plugin
  from tensorboard.plugins.text import text_plugin
  from tensorboard.util import test_util
label_desc: Use image node_id 5 for calling the TextPluginTest obj's underlying member method code with example usage: obj.testIndex() without return types