class_docstr: Tests the TensorBoard program.
code: def testPlugins_pluginLoader(self):
      loader = core_plugin.CorePluginLoader()
      tb = program.TensorBoard(
          plugins=[loader],
          assets_zip_provider=fake_asset_provider,
      )
      self.assertIs(tb.plugin_loaders[0], loader)
  
imports: import argparse
  import io
  import sys
  from unittest import mock
  from tensorboard import program
  from tensorboard import test
  from tensorboard.plugins import base_plugin
  from tensorboard.plugins.core import core_plugin
label_desc: Use image node_id 3 for calling the TensorBoardTest obj's underlying member method code with example usage: obj.testPlugins_pluginLoader() without return types