code: def setUp(self):
      self.client = unittest.mock.MagicMock()
  
      client._client_manager.clients["discuss"] = self.client
  
      self.observed_request = None
  
      self.mock_response = glm.GenerateMessageResponse(
          candidates=[
              glm.Message(content="a", author="1"),
              glm.Message(content="b", author="1"),
              glm.Message(content="c", author="1"),
          ],
      )
  
      def fake_generate_message(
          request: glm.GenerateMessageRequest,
      ) -> glm.GenerateMessageResponse:
          self.observed_request = request
          response = copy.copy(self.mock_response)
          response.messages = request.prompt.messages
          return response
  
      self.client.generate_message = fake_generate_message
  
imports: import copy
  import unittest.mock
  import google.ai.generativelanguage
  from google.generativeai import discuss
  from google.generativeai import client
  import google.generativeai
  from google.generativeai.types import safety_types
  from absl.testing import absltest
  from absl.testing import parameterized
label_desc: Use image node_id 1 for calling the UnitTests obj's underlying member method code with example usage: obj.setUp() and returns: response