code: def testServeExecutionDigests400ResponseIfRunParamIsNotSpecified(
      self,
  ):
      response = self.server.get(
          # `run` parameter is not specified here.
          _ROUTE_PREFIX
          + "/execution/digests?begin=0&end=0"
      )
      self.assertEqual(400, response.status_code)
      self.assertEqual(
          "application/json", response.headers.get("content-type")
      )
      self.assertEqual(
          json.loads(response.get_data()),
          {"error": "run parameter is not provided"},
      )
  
imports: import collections
  import json
  import os
  import socket
  import threading
  import tensorflow
  from werkzeug import test
  from werkzeug import wrappers
  from tensorboard.backend import application
  from tensorboard.plugins import base_plugin
  from tensorboard.plugins.debugger_v2 import debug_data_multiplexer
  from tensorboard.plugins.debugger_v2 import debugger_v2_plugin
label_desc: Use image node_id 23 for calling the DebuggerV2PluginTest obj's underlying member method code with example usage: obj.testServeExecutionDigests400ResponseIfRunParamIsNotSpecified() without return types